Magnetic field-ultrasonic assisted laser polishing composite manufacturing method and device

Abstract

A kind of magnetic field-ultrasonic auxiliary laser polishing composite manufacturing method, comprising the following steps: S1: the workpiece to be processed is placed on processing table top;S2: adjust magnetic field direction by the movement of electromagnet on guide rail;S3: control mobile assembly to align the workpiece to be processed position with laser;S4: control lifting assembly to drive processing table top to lift, so that the focal point of laser is aligned with the surface of workpiece to be polished position;S5: set magnetic field intensity, set the frequency and amplitude of ultrasonic generating assembly, set processing path and set the refrigeration temperature of refrigeration assembly;S6: start electromagnet, ultrasonic generating assembly, mobile assembly and laser, mobile assembly drives processing platform to move according to processing path, and polishing processing is carried out.The present application provides a kind of magnetic field-ultrasonic auxiliary laser polishing composite manufacturing device.The present application will quickly improve the surface quality and precision of workpiece.

Description

Technical Field

[0001] This invention belongs to the field of ultra-precision polishing composite manufacturing, and in particular, it designs a magnetic field-ultrasound-assisted laser polishing composite manufacturing method and device. Background Technology

[0002] Laser polishing is an emerging surface polishing technology that has attracted much attention from researchers both domestically and internationally due to its advantages such as being pollution-free, having a wide range of processing objects, providing stable polishing quality, and being easily automated. Its principle is that a laser melts or evaporates the surface layer of the material, driving the molten metal to flow under the action of capillary force or thermocapillary force, thus filling the valleys with the peaks and obtaining a smooth surface.

[0003] When performing laser polishing on alloy metals, the process is categorized into two states based on the thickness of the molten layer and the heat-affected layer: a shallow molten state and an over-molten state. In the shallow molten state, the workpiece absorbs laser energy only up to its melting point, resulting in a relatively small surface roughness, but the rate of reduction in surface roughness is small. In the over-molten state, the workpiece material absorbs more energy, and due to the influence of temperature gradient and thermocapillary force, ripples will appear on the solidified surface.

[0004] The prior art publication number CN117226307A discloses a multi-energy field assisted laser processing device and method for printed circuit boards. The processing device includes a laser, a height-adjustable processing table, and an outer casing. The laser is positioned above the processing table, and the processing table is equipped with the moving end of a sub-moving component. The height-adjustable processing table allows the laser focus to change with the processing depth when processing deep holes. The moving component can drive the processing table to move laterally and longitudinally. The outer casing is fitted over the processing table, and a coil winding is disposed on the inner wall of the outer casing. The coil winding generates a magnetic field, causing charged particles in the plasma generated during laser processing to accelerate outward within the magnetic field. An ultrasonic generator and a cooling component are mounted on the processing table. This invention combines four functions—magnetic field, ultrasound, cryogenics, and the height adjustment of the processing table—with laser processing. In this invention, ultrasonic vibration is applied to the processing table to cause radial movement of the laser focus, and the magnetic field direction is perpendicular to the processing table from bottom to top, making it more suitable for processing such as laser drilling.

[0005] Chinese Patent Publication No. CN109530911A discloses an axial ultrasonic vibration lens-assisted laser processing device. This device includes a laser generator and an ultrasonic generator. The output end of the laser generator is connected to one end of a collimating lens on a laser working head via a light terminal. The laser working head comprises a collimating lens, an ultrasonic transducer, an amplitude transformer, and a focusing lens mechanism. The laser working head is fixed to the machine tool spindle by the collimating lens, clips, and hexagonal bolts. The other end of the collimating lens is connected to one end of the ultrasonic transducer, which is connected to the ultrasonic generator. The other end of the ultrasonic transducer is connected to one end of the amplitude transformer, which is connected to the focusing lens mechanism. This maximizes the amplitude of the ultrasonic waves acting on the lens, resulting in a wider vibration range and maximizing the focal height of the focused column. A higher focal height effectively improves the quality and efficiency of laser processing. This invention effectively solves the problems caused by deviations in the laser focus position due to factors such as uneven workpiece surface, workpiece clamping method, machine tool geometric errors, machine tool deformation under load, and workpiece thermal deformation during processing. This improves the surface quality, processing accuracy, and processing efficiency of laser processing. However, there is still room for optimization in addressing issues such as the secondary roughness caused by the surface tension gradient of the molten pool, which causes the upper fluid in the central region of the molten pool to flow towards the edge, and the formation of porosity defects in the molten pool due to insufficient upward velocity preventing escape before solidification.

[0006] Chinese Patent Publication No. CN114192985A discloses a magnetic field-assisted laser polishing device and method, comprising a cabinet; a worktable installed within the cabinet, the worktable having a workpiece positioning area for placing the workpiece; a magnetic mechanism for placing the workpiece in a magnetic field; and a laser system installed within the cabinet, including a first laser emitting mechanism for preheating the workpiece surface, a second laser emitting mechanism for polishing the workpiece surface, and a third laser emitting mechanism for annealing the workpiece surface. The magnetic field-assisted laser polishing device provided by this invention effectively reduces the surface roughness of the workpiece and improves the polishing effect by combining the magnetic field generated by the magnetic mechanism and the laser emitted by the laser system at the workpiece. However, since the magnetic mechanism has a fixed position for workpieces of different sizes and shapes, a more flexible, movable magnetic mechanism is needed to adjust parameters such as the direction of the magnetic field during workpiece processing.

[0007] Chinese Patent Publication No. CN109967864A discloses a magnetic field-assisted laser polishing device based on existing laser processing equipment, belonging to the field of laser processing technology. It mainly includes a magnetic field coil, a cooling water inlet, a cooling water outlet, a coil energizing connector, a linear guide rail, a support, a handle, and a processing platform. Compared with existing devices, the technological breakthrough of this invention lies in combining existing laser processing equipment with magnetic field-assisted technology and applying it to the field of laser polishing. This not only allows for adjusting the distance between the two magnetic field coils according to the size of the workpiece, solving the problem of processing large and complex-shaped workpieces in magnetic field-assisted laser polishing, but also addresses defects such as cracks, uneven ripples, overlapping stripes, and porosity caused by molten pool splashing, uneven cooling temperature, and large polishing area during polishing, effectively reducing the surface roughness of metal components. Clearly, this patent belongs to magnetic field-assisted laser polishing manufacturing, and uses a relatively flexible, movable magnetic field coil position to incorporate the magnetic field into laser polishing. However, whether introducing both ultrasound and magnetic fields into laser polishing can further improve the surface quality and mechanical properties of the workpiece after polishing requires further investigation.

[0008] Faced with the above problems, the current production process only improves the polishing quality by adjusting the laser parameters or by using a single energy field to assist laser polishing. However, there is still room for further improvement in the post-polishing quality and mechanical properties of the workpiece surface. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, further reduce the roughness of laser-polished workpieces, and effectively solve the problems caused by the unevenness of the workpiece surface, workpiece clamping method, machine tool geometric errors, machine tool deformation under load, and thermal deformation of the workpiece during processing, which lead to deviations in the laser focus position and affect processing accuracy and quality, this invention provides a magnetic field-ultrasound-assisted laser polishing composite manufacturing method and apparatus. It also aims to suppress the formation of secondary roughness and porosity after polishing, refine grain size, enhance ultimate tensile strength, increase elongation, and optimize the mechanical properties of parts.

[0010] The technical solution adopted by this invention to solve its technical problem is:

[0011] A magnetic field-ultrasound-assisted laser polishing composite manufacturing method includes the following steps:

[0012] S1: Place the workpiece to be processed on the processing table;

[0013] S2: Adjust the direction of the magnetic field by moving the electromagnet on the guide rail;

[0014] S3: Control the moving component to align the workpiece to be processed position with the laser;

[0015] S4: Control the lifting assembly to raise and lower the processing table so that the laser focus is aligned with the surface of the workpiece to be polished;

[0016] S5: Set the magnetic field strength, set the frequency and amplitude of the ultrasonic generator, set the processing path, and set the cooling temperature of the cooling component;

[0017] S6: Start the electromagnet, ultrasonic generator, moving assembly, and laser. The moving assembly drives the processing platform to move along the processing path to perform polishing.

[0018] Furthermore, in S5, the magnetic field strength is set, and the electromagnet is activated to generate a steady-state magnetic field with adjustable magnetic induction intensity. The magnetic field acts on the surface of the workpiece to generate a Lorentz force that is opposite to the direction of motion of the melt perpendicular to the magnetic field, which inhibits the flow of the molten pool fluid perpendicular to the magnetic field direction and accelerates the escape of gas in the molten pool. The frequency and amplitude of the ultrasonic generator are set, and the ultrasonic generator is activated to make the focusing lens perform axial ultrasonic vibration, which changes the spot diameter on the surface of the workpiece and forms an intermittent laser polishing composite manufacturing process on the surface of the workpiece.

[0019] Furthermore, in step S6, the polishing process is performed by coupling the magnetic field, ultrasound, and laser fields. This reduces the impact of the laser focus position shifting vertically during the processing, suppresses the formation of the second roughness and pores after workpiece polishing, thereby improving processing accuracy and quality, refining grain size, optimizing the mechanical properties of parts, and further reducing the roughness of the workpiece after laser polishing.

[0020] Preferably, in S5 and S6, the processing path is an S-shaped bidirectional scanning path.

[0021] A magnetic field-ultrasound-assisted laser polishing composite manufacturing device includes a laser, a movable processing table, a laser working device, and a magnetic mechanism. The laser is fixedly mounted above the processing table to generate laser light, and its output end is connected to a collimating lens of the laser working device via an optical fiber terminal. The laser working device is located above the workstation of the processing table, and its piezoelectric ceramic is connected to the output of an ultrasonic generator. The magnetic mechanism is located outside the processing table. The processing table is connected to a lifting assembly for raising and lowering the processing table, and the lifting assembly is connected to a moving assembly for driving the processing table to move laterally and longitudinally. A cooling assembly is provided on the processing table.

[0022] Furthermore, the laser working device includes a collimating lens, a front mass cover, electrode material, piezoelectric ceramic material, a rear mass cover, an amplitude transformer, a lens tube, and a focusing lens. The laser working device is fixedly mounted on a frame. The other end of the collimating lens is connected to the rear mass cover, the front mass cover is connected to one end of the amplitude transformer, and the other end of the amplitude transformer is connected to the lens tube. The piezoelectric ceramic material and the electrode material are alternately arranged between the front and rear mass covers. The front and rear mass covers clamp and fix the piezoelectric ceramic material and the electrode material through connecting posts and double-ended studs.

[0023] The processing table is mounted on the moving end of the moving component, and the moving component can drive the processing table to move laterally and longitudinally at least; preferably, the moving component is a two-dimensional moving platform.

[0024] The magnetic mechanism is located on the outside of the processing table. The magnetic mechanism includes a housing and an electromagnet. A guide rail is provided inside the housing. The electromagnet is installed on the guide rail and can move along the guide rail. The electromagnet is used to generate a uniform magnetic field from the N pole to the S pole.

[0025] A cooling component is provided on the processing table surface;

[0026] Furthermore, a slider is provided at the lower end of the processing table, the processing table is connected to the slider, and the slider is installed on the lifting end of the lifting assembly.

[0027] Preferably, the lower end face of the processing table is provided with a threaded hole, and the slider has a stepped hole that mates with it. A bolt is provided in the stepped hole and the bolt is connected to the threaded hole.

[0028] Preferably, the lifting end includes a servo motor and a vertical guide rod, and the slider is disposed on the vertical guide rod.

[0029] In the laser working device, the mechanical impedance of the front mass cover should be as low as possible, while the mechanical impedance of the rear mass cover should be as high as possible, and the mechanical impedance of the piezoelectric ceramic material should be between them; therefore, the front mass cover is usually made of light metal, while the rear mass cover is usually made of heavy metal.

[0030] The laser working device is mounted and fixed on the frame and can be moved up, down, left, and right by a chain. The laser beam directly irradiates the workpiece through the laser working device, so it is a hollow structure. The electrode material and the piezoelectric ceramic material are both ring-shaped sheets, and the amplitude transformer has through holes inside.

[0031] The device also includes a control system. The laser, servo system, laser working device, and magnetic mechanism are all communicatively connected to the control system. The communicative connection means that the control system can send control commands to the controlled device.

[0032] The device also includes a frame, on which the moving component and the lifting component are mounted, and the moving component moves via a chain.

[0033] The refrigeration assembly also includes a water-cooled plate and a thermoelectric cooling plate. The water-cooled plate is mounted on the processing table and has a thermoelectric cooling plate, which includes a cold side and a hot side. The cold side is in contact with the workpiece and the hot side is in contact with the water-cooled plate. The water-cooled plate has a coolant inlet and a coolant outlet.

[0034] The beneficial effects of this invention are mainly reflected in:

[0035] 1. By integrating magnetic field and ultrasonic laser polishing, three-field coupled composite manufacturing can be achieved. In addition, laser polishing can still be performed by controlling only one energy field.

[0036] 2. By incorporating an ultrasonic generator component within the lens, the piezoelectric ceramic converts the electrical signal emitted by the ultrasonic generator into mechanical vibrations at ultrasonic frequencies. These vibrations are amplified by an amplitude transformer and transmitted to the focusing lens. The focusing lens vibrates at the ultrasonic frequency, altering the spot diameter on the workpiece surface. This results in a change in the laser energy density on the workpiece surface, affecting the temperature amplitude of the molten pool. Consequently, an intermittent laser polishing process is formed on the workpiece surface, effectively preventing over-melting of the polished surface and improving the surface quality of the workpiece.

[0037] 3. By setting an electromagnet on the machining table to generate a magnetic field, the magnetic field acts on the surface of the workpiece. The Lorentz force generated by the magnetic field is always opposite to the direction of motion of the melt perpendicular to the magnetic field, thereby inhibiting the flow of the molten pool fluid perpendicular to the magnetic field. Moreover, the inhibition effect is more obvious as the steady-state magnetic field strength increases. It promotes crystal nucleation in the molten pool during solidification, making the solidified grains more refined, thereby inhibiting the formation of the second roughness on the workpiece surface.

[0038] 4. This invention achieves composite polishing manufacturing by coupling magnetic field, ultrasound, and laser fields, further reducing the roughness of laser-polished workpieces. It effectively solves the problems caused by uneven workpiece surfaces, workpiece clamping methods, machine tool geometric errors, machine tool deformation under load, and thermal deformation of the workpiece during processing, all of which lead to deviations in the laser focus position and affect processing accuracy and quality. It also suppresses the formation of secondary roughness and porosity after polishing, refines grain size, strengthens ultimate tensile strength, increases elongation, and optimizes the mechanical properties of the parts. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of this device.

[0040] Figure 2 This is a schematic diagram of a laser working device.

[0041] Figure 3This is a schematic diagram of a magnetic mechanism.

[0042] Figure 4 This is a schematic diagram of the magnetic mechanism and the machining table.

[0043] Figure 5 This is a comparison chart showing the focusing effect of a conventional laser beam and the focusing effect of a laser beam assisted by ultrasonic vibration.

[0044] Figure 6 A schematic diagram illustrating the principle of magnetic field assistance.

[0045] Figure 7 This is a schematic diagram of the polishing method in a magnetic field-ultrasound-assisted laser polishing composite manufacturing device.

[0046] Figure 8 This is a microscopic schematic diagram of a workpiece polished by magnetic field-ultrasound-assisted laser polishing (a portion of the workpiece's molten pool is shown).

[0047] Figure 9 This is a schematic diagram of the scanning path for workpiece processing using magnetic field-ultrasound assisted laser polishing.

[0048] The attached diagram is labeled as follows: 1. Frame; 2. Laser; 3. Fiber optic cable; 4. Laser working device; 5. Cooling component; 6. Processing table; 7. Electromagnet; 8. Housing; 9. Slider; 10. Right vertical guide rod; 11. Servo motor; 12. Fixing block; 13. Moving component; 14. Left vertical guide rod; 15. Lead screw shaft; 16. Threaded hole; 17. Electromagnet base; 18. Control system; 19. Guide rail; 20. Workpiece to be processed; 21. 21. Laser source; 22. Laser beam; 23. Laser focusing point; 24. Workpiece molten pool; 25. Vortex convection inside the molten pool; 26. Laser output optical cable; 27. Chain; 28. Ultrasonic generator; 401. Washer; 402. Focusing lens; 403. Lens tube; 404. Amplitude rod; 405. Front mass cover; 406. Piezoelectric ceramic material; 407. Electrode material; 408. Rear mass cover; 409. Collimator. Detailed Implementation

[0049] The present invention will now be further described with reference to the accompanying drawings.

[0050] Example 1

[0051] Reference Figures 1-9A magnetic field-ultrasound-assisted laser polishing composite manufacturing device includes a laser 2, a height-adjustable processing table 6, a laser working device 4, and a magnetic mechanism. The laser is fixedly installed above the processing table to generate laser light, and the output end of the laser is connected to the collimating lens of the laser working device through an optical fiber terminal. The laser working device is located above the workstation of the processing table, and the piezoelectric ceramic of the laser working device is connected to the output of the ultrasonic generator. The magnetic mechanism is located on the outside of the processing table. The processing table is connected to a lifting assembly for driving the processing table to move up and down. The lifting assembly is connected to a moving assembly for driving the processing table to move laterally and longitudinally. A cooling assembly is provided on the processing table.

[0052] The laser 2 is fixedly mounted above the processing table 6, and the processing table is mounted on the moving end of the moving component 13. The moving component can at least drive the processing table 6 to move in the horizontal direction.

[0053] The magnetic mechanism is located outside the processing table 6. The magnetic mechanism includes a housing 8 and an electromagnet 7. A guide rail 19 is provided inside the housing 8, and the electromagnet 7 is mounted on the guide rail 19 and can move along the guide rail. The electromagnet 7 is used to generate a uniform horizontal magnetic field from the N pole to the S pole. The magnitude of the magnetic field can be changed by adjusting the electromagnet current. The housing 8 is located outside the processing table 6, and the electromagnet 7 is arranged on the plane of the housing 8. The guide rail 19 is located below the electromagnet 7, allowing the electromagnet 7 to move on the guide rail 19, thereby changing the direction of the magnetic field. When the laser 2 polishes the workpiece surface, the Lorentz force generated by the magnetic field produced by the electromagnet 7 is always opposite to the direction of motion of the melt perpendicular to the magnetic field direction, thus suppressing the flow of the molten pool fluid perpendicular to the magnetic field direction. The suppression effect is more pronounced as the steady-state magnetic field strength increases. This promotes crystal nucleation during the solidification process of the molten pool, resulting in finer grains after solidification, thereby suppressing the formation of the second roughness on the workpiece surface and improving the surface quality of the workpiece after laser polishing.

[0054] The laser working device 4 is equipped with a piezoelectric ceramic material 406. The piezoelectric effect of the material converts electrical signals into mechanical vibrations. The frequency and amplitude of the mechanical vibrations are changed by adjusting the magnitude of the electrical signal through the control system 18. When the laser 2 polishes the workpiece, the laser 2 generates laser light. The laser light is transmitted to the output end of the optical fiber and emitted as a laser beam. The laser beam passes through the collimating lens 409 and sequentially through the rear mass cover 408, electrode material 407, piezoelectric ceramic material 406, front mass cover 405, and amplitude transformer 404. Finally, it is focused onto the workpiece by the focusing lens 402. The focusing lens vibrates at an ultrasonic frequency, which makes the laser energy density on the workpiece surface change periodically. This helps to increase the heat dissipation and heat transfer time of the polishing material and improve the polishing quality of the workpiece surface.

[0055] The laser working device 4 is mounted on the frame 1 and can be moved up, down, left, and right by the chain 27. The laser beam directly irradiates the workpiece through the laser working device 4, so it is a hollow structure. The electrode material 407 and the piezoelectric ceramic material 406 are both annular sheets, and the amplitude rod 404 has through holes inside.

[0056] A cooling assembly 5 is provided on the processing table 6. The cooling assembly 5 includes a water-cooled plate and thermoelectric cooling plates. The water-cooled plate is installed on the side of the processing table. The thermoelectric cooling plates are laid on the water-cooled plate. The thermoelectric cooling plates include a cold side and a hot side. The cold side is in contact with the workpiece, and the hot side is in contact with the water-cooled plate. The water-cooled plate has a coolant inlet and a coolant outlet. The water-cooled plate is used to exchange heat with the hot side to reduce the temperature of the hot side.

[0057] In this embodiment, the thermoelectric cooling chip is communicatively connected to the control system 18. The required low-temperature processing temperature is set by the control system. The communicative connection means that the controller 14 can send control commands to the controlled device.

[0058] The magnetic field-ultrasound-assisted laser polishing composite manufacturing device of this embodiment integrates the three functions of magnetic field, ultrasound and the movement of the processing table 6 with laser polishing, and can realize multiple coupled laser polishing.

[0059] In this embodiment, the mobile component 13 is a two-dimensional mobile platform.

[0060] In this embodiment, a slider 9 is provided at the lower end of the processing table 6. The processing table 6 is connected to the slider 9. The slider 9 is installed at the lifting end of the lifting assembly. The lifting function is achieved by sliding the slider 9 up and down on the left vertical guide rod 14 and the right vertical guide rod 10.

[0061] When the laser 2 polishes the workpiece, the lifting component drives the processing table 6 to move, thereby realizing the up and down movement of the laser focus during workpiece surface polishing to adapt to laser polishing of workpieces of different thicknesses. The moving component 13 drives the processing table 6 to move horizontally, thereby realizing the change of the laser irradiation position on the workpiece surface according to the set path, thus completing the workpiece polishing work.

[0062] In this embodiment, the lower end face of the processing table 6 is provided with a threaded hole 16, the slider 9 is provided with a stepped hole that matches it, a bolt is provided in the stepped hole, the bolt is connected to the threaded hole 16, and the outer shell 8 is provided with a through hole for the bolt to pass through.

[0063] In this embodiment, the lifting end includes a servo motor 11 and a vertical guide rod (left) 14 and a vertical guide rod (right) 10. The slider 9 is sleeved on the vertical guide rod (left) 14 and the vertical guide rod (right) 10. The output shaft of the servo motor 11 is a lead screw shaft 15. The slider 9 is sleeved on the lead screw shaft 15 and threadedly engaged with it. The servo motor 11 is mounted on the frame through a fixing block 12.

[0064] In this embodiment, the device further includes a control system 18. The laser 2, laser working device 4, electromagnet 7, servo motor 11, and moving component 13 are all communicatively connected to the control system 18. The communicative connection means that the control system 18 can send control commands to the control device.

[0065] The device also includes a frame 1, and the moving component 13 and the lifting component are both mounted on the frame 1. The moving component 13 moves via a chain.

[0066] Example 2

[0067] Reference Figures 1-9 A magnetic field-ultrasound-assisted laser polishing composite manufacturing method includes the following steps:

[0068] S1: Place the workpiece to be processed on the processing table 6;

[0069] S2: Adjust the direction of the magnetic field by moving the electromagnet on the guide rail;

[0070] S3: Control the moving component 13 to align the workpiece to be processed position with the laser 1;

[0071] S4: Control the lifting assembly to lift the processing table 6, so that the focus of the laser 1 is aligned with the surface of the workpiece to be polished.

[0072] S5: Set the magnetic field strength, set the frequency and amplitude of the ultrasonic generator, set the processing path, and set the cooling temperature of the cooling component;

[0073] S6: Start the electromagnet 7, ultrasonic generator, moving component 13 and laser 2. The moving component 13 drives the processing platform to move along the processing path to perform polishing.

[0074] The embodiments described in this specification are merely examples of implementations of the inventive concept and are for illustrative purposes only. The scope of protection of this invention should not be considered limited to the specific forms described in these embodiments; rather, it extends to equivalent technical means conceived by those skilled in the art based on the inventive concept.

Claims

1. A magnetic field-ultrasound-assisted laser polishing composite manufacturing method, characterized in that, The method includes the following steps: S1: Place the workpiece to be processed on the processing table; S2: The direction of the magnetic field is adjusted by the movement of the electromagnet on the guide rail. The magnetic mechanism includes a housing and an electromagnet, and the guide rail is provided inside the housing. S3: Control the moving component to align the workpiece to be processed position with the laser; S4: Control the lifting assembly to raise and lower the processing table so that the laser focus is aligned with the surface of the workpiece to be polished; S5: Set the magnetic field strength, set the frequency and amplitude of the ultrasonic generator, set the processing path, and set the cooling temperature of the cooling component; S6: Start the electromagnet, ultrasonic generator, moving component and laser. The moving component drives the processing platform to move along the processing path to perform polishing. In step S5, the magnetic field strength is set, and the electromagnet is activated to generate a steady-state magnetic field with adjustable magnetic induction intensity. The magnetic field acts on the workpiece surface to generate a Lorentz force that is opposite to the direction of motion of the melt perpendicular to the magnetic field direction, which inhibits the flow of the molten pool fluid perpendicular to the magnetic field direction and accelerates the escape of gas in the molten pool. The frequency and amplitude of the ultrasonic generator are set, and the ultrasonic generator is activated to make the focusing lens perform axial ultrasonic vibration, which changes the spot diameter on the workpiece surface and forms an intermittent laser polishing composite manufacturing process on the workpiece surface. In step S6, the polishing process is performed by coupling the magnetic field, ultrasound, and laser fields. This reduces the impact of the laser focus position shift during the processing, suppresses the formation of the second roughness and pores after polishing, and improves the processing accuracy and quality, refines the grain size, optimizes the mechanical properties of the parts, and further reduces the roughness of the workpiece after laser polishing.

2. An apparatus for implementing the magnetic field-ultrasound-assisted laser polishing composite manufacturing method as described in claim 1, characterized in that, The device includes a laser, a movable processing table, a laser working device, and a magnetic mechanism. The laser is fixedly mounted above the processing table to generate laser light. The output end of the laser is connected to the collimating lens of the laser working device via an optical fiber terminal. The laser working device is located above the workstation on the processing table. The piezoelectric ceramic of the laser working device is connected to the output of an ultrasonic generator. The magnetic mechanism is located on the outside of the processing table. The processing table is connected to a lifting assembly for raising and lowering the processing table. The lifting assembly is connected to a moving assembly for driving the processing table to move laterally and longitudinally. A cooling assembly is provided on the processing table. The magnetic mechanism includes a housing and an electromagnet. A guide rail is provided inside the housing. The guide rail is an annular guide rail around the perimeter of the processing table. The electromagnet is mounted on the guide rail and can move along the guide rail. The electromagnet is used to generate a uniform magnetic field from the N pole to the S pole.

3. The apparatus as described in claim 2, characterized in that, The laser working device includes a collimating lens, a front mass cover, electrode material, piezoelectric ceramic material, a rear mass cover, an amplitude transformer, a lens tube, and a focusing lens. The laser working device is fixedly mounted on a frame. The other end of the collimating lens is connected to the rear mass cover, the front mass cover is connected to one end of the amplitude transformer, and the other end of the amplitude transformer is connected to the lens tube. The piezoelectric ceramic material and electrode material are alternately arranged between the front and rear mass covers. The front and rear mass covers clamp and fix the piezoelectric ceramic material and electrode material through connecting posts and double-ended studs. The piezoelectric ceramic material and electrode material are arranged at intervals.

4. The apparatus as described in claim 2 or 3, characterized in that, A slider is provided at the lower end of the processing table, the processing table is connected to the slider, the slider is installed on the lifting end of the lifting assembly, the lifting end includes a servo motor and a vertical guide rod, and the slider is set on the vertical guide rod.

5. The apparatus as described in claim 3, characterized in that, The laser working device is mounted and fixed on the frame and can be moved up, down, left, and right by a chain. The laser beam directly irradiates the workpiece through the laser working device, so it is a hollow structure. The electrode material and the piezoelectric ceramic material are both ring-shaped sheets, and the amplitude transformer has through holes inside.

6. The apparatus as claimed in claim 2 or 3, characterized in that, The device also includes a control system. The laser, servo system, laser working device, and magnetic mechanism are all communicatively connected to the control system. The communicative connection means that the control system can send control commands to the controlled device.

7. The apparatus as claimed in claim 2 or 3, characterized in that, The refrigeration assembly also includes a water-cooled plate and a thermoelectric cooling plate. The water-cooled plate is mounted on the processing table and has a thermoelectric cooling plate, which includes a cold side and a hot side. The cold side is in contact with the workpiece and the hot side is in contact with the water-cooled plate. The water-cooled plate has a coolant inlet and a coolant outlet.

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