Modulation pulse laser processing method and system based on scanning graph and frequency adjustment

Abstract

The invention discloses a modulation pulse laser processing method and system based on scanning graphs and frequency adjustment, and belongs to the field of laser processing. The modulation pulse laser processing method comprises the following steps: setting laser power, scanning frequency, scanning amplitude and duration time of each section in different sections of an energy field to enable the laser power, the scanning frequency and the scanning amplitude of continuous laser to periodically and alternately change to generate modulation pulse laser; generating a preset laser oscillation track according to a preset laser scanning pattern, the processing speed and the modulation frequency and the modulation duty ratio of the modulation pulse laser; and enabling the modulation pulse laser to act on the to-be-processed workpiece according to a preset laser oscillation track to form a molten pool, and carrying out laser processing. On the basis of existing laser beam oscillation scanning, a scanning laser pulse effect is formed. The method has the characteristics of eliminating pores by scanning laser, refining crystal grains and being low in pulse laser heat effect at the same time, and the mechanical property is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of laser processing, and more particularly, to a modulated pulse laser processing method and system based on scanning patterns and frequency adjustment. BACKGROUND

[0002] Scanning laser can expand the energy range of action and enhance the stirring effect of the molten pool by laser beam oscillation, thereby improving the gap tolerance, forming quality and microstructure, and even reducing defects such as pores and cracks, and has been widely used in laser welding, laser-arc hybrid welding and additive manufacturing and other laser processing fields.

[0003] However, the existing scanning laser actually disperses the heat input while expanding the range of action, and the laser power must be increased to ensure that the substrate is fully melted and well wet-spread. However, increasing the overall heat input will directly cause an increase in the tendency of thermal cracking at the laser processing position, partially offsetting the effect of scattering dendrites by scanning stirring and inhibiting cracks. Therefore, it is necessary to find a better light field scanning mode that retains the existing advantages while reducing heat input.

[0004] Relatively speaking, pulsed laser is a "cold processing" technology that releases high energy in a short time through light field modulation, has the advantages of small heating effect and high efficiency, and can achieve more precise energy field regulation through parameters such as period, pulse width, and duty cycle. However, the sudden change in laser power in pulsed laser will cause the opening and closing of the laser keyhole, greatly affecting the stability of the small hole, thereby reducing the processing quality.

[0005] Therefore, modulating the scanning laser beam into a pulse mode can effectively reduce the overall heat input during laser processing and better utilize the ability of scanning laser to refine grains and inhibit pore and crack defects. SUMMARY

[0006] In view of the defects of the related art, the purpose of the present application is to provide a modulated pulse laser processing method and system based on scanning patterns and frequency adjustment, aiming to modulate the existing scanning laser beam into a pulse mode, so that it has the characteristics of both continuous laser and pulsed laser, and improve the efficiency and quality of laser processing.

[0007] To achieve the above purpose, in a first aspect, the present application provides a modulated pulse laser processing method based on scanning patterns and frequency adjustment, comprising the following steps: S1, generating a modulated pulse laser by periodically alternating the laser power, scanning frequency, and scanning amplitude of the continuous laser by setting the laser power, scanning frequency, scanning amplitude, and duration of each section in the different sections of the energy field; the modulation frequency and modulation duty cycle of the modulated pulse laser are determined according to the laser power, scanning frequency, and scanning amplitude of the continuous laser; S2, generating a preset laser oscillation track according to a preset laser scanning pattern, a processing speed, and a modulation frequency and a modulation duty cycle of the modulated pulsed laser; S3, causing the modulated pulsed laser to act on the workpiece to be processed according to the preset laser oscillation track and form a molten pool, and performing laser processing.

[0008] Optionally, before step S1, the method further comprises: adjusting an incident angle and a defocusing amount of the continuous laser to cause the laser to act on a starting position of the workpiece to be processed.

[0009] Optionally, the adjustment range of the incident angle is -50°-50°, and the adjustment range of the defocusing amount is -30-30mm.

[0010] Optionally, the scanning frequency ranges from 0 to 2000Hz, the scanning amplitude ranges from 0 to 20mm, and the laser power ranges from 10 to 50kW.

[0011] Optionally, the processing speed ranges from 0.1 to 30m / min.

[0012] In a second aspect, the present application further provides a laser processing control system for performing the modulated pulsed laser processing method based on a scanning pattern and frequency adjustment according to any one of the first aspect, comprising a laser, a transmission optical fiber, a galvanometer focusing device, a galvanometer lens group, a galvanometer controller, a motion mechanism, a control cabinet and a workpiece to be processed. The control cabinet is connected with the laser, the galvanometer controller and the motion mechanism respectively, the laser is connected with the galvanometer focusing device through the transmission optical fiber, and the galvanometer controller is connected with the galvanometer focusing device. The motion mechanism is used for clamping the galvanometer focusing device and driving the galvanometer focusing device to move according to the control signal of the control cabinet, so that the laser beam acting on the workpiece to be processed moves at a preset processing speed. The galvanometer controller is used for controlling the galvanometer lens group in the galvanometer focusing device to move according to preset parameters, the control cabinet is used for controlling the power of the laser according to preset parameters, and the preset parameters include laser power, scanning frequency, scanning amplitude and duration of each section in different sections of energy field, and laser scanning pattern. The galvanometer lens group is used for converting the continuous laser generated by the laser into modulated pulsed laser to act on the workpiece to be processed.

[0013] In a third aspect, the present application further provides a laser-arc hybrid welding system, comprising an arc welding machine, an arc welding gun, a connecting clamp and the laser processing control system according to the second aspect. The arc welding torch is connected to the galvanometer focusing device in the laser processing control system via the connecting clamp; The arc welding machine is used to control the arc welding gun to generate an electric arc, so that the electric arc and the modulated pulse laser generated in the laser processing control system work together on the workpiece to be processed.

[0014] Fourthly, the present invention also provides a laser directional energy deposition system, including a powder feeding head, a powder feeder, and the laser processing control system described in the second aspect; The powder feeding head is connected to the powder feeder; The powder feeding head is installed below the galvanometer focusing device in the laser processing control system and is used to transport the powder in the powder feeder to the molten pool area on the workpiece to be processed to form a deposition layer.

[0015] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects: 1. This invention provides a modulated pulse laser processing method based on scanning pattern and frequency adjustment. By setting the laser power, scanning frequency, scanning amplitude, and duration of each segment in different energy field sections, the laser power, scanning frequency, and scanning amplitude of the continuous laser undergo periodic alternation, thereby generating a modulated pulse laser. A preset laser oscillation trajectory can be set according to the preset laser scanning pattern, processing speed, and laser parameters. Using a modulated pulse laser for laser processing of the workpiece maintains stable laser power throughout the process, effectively avoiding the frequent opening and closing of small holes caused by the periodic switching or large-range fluctuations of laser power in traditional modulated pulse modes, which induces defects such as spatter, edge biting, and porosity. By employing modulated pulsed lasers, the melting range can be increased through high-frequency / large-amplitude large-sweep field rotation, thus ordering the molten pool flow, enhancing molten pool stirring ability, and consequently breaking dendrites, suppressing porosity, and improving the uniformity of precipitated phase distribution. Furthermore, the high energy density advantage of low-frequency / small-amplitude peaks improves energy utilization efficiency, achieving the same processing effect with reduced overall heat input, avoiding problems such as molten pool instability, elemental burn-off, and thermal cracking caused by overheating. Modulating the scanning laser beam into a pulsed mode can effectively reduce the overall heat input during laser processing, better leveraging the scanning laser's ability to refine grains and suppress porosity and crack defects.

[0016] 2. This invention provides a modulated pulsed laser processing method based on scanning pattern and frequency adjustment. The modulated pulsed laser generated by this method has multiple variable parameters such as scanning pattern, local scanning frequency, local scanning amplitude, modulation frequency, and modulation duty cycle. Through local parameter adjustment or multi-parameter synergistic control, uniform energy distribution or quantitative adjustment of laser energy distribution can be achieved. This helps to more accurately control the accumulated energy at different processing positions, thereby further improving the active control capability and consistency of the process.

[0017] 3. This invention provides a modulated pulsed laser processing method based on scanning pattern and frequency adjustment. The energy density of the modulated pulsed laser changes periodically in the laser processing direction. That is, the molten pool heat flow will form a new longitudinal surge or axial oscillation on the basis of the original laser radial scanning and rotating stirring, so that the scanning stirring is transformed from two-dimensional to three-dimensional, realizing three-dimensional, all-round orderly stirring of the molten pool heat flow. This can not only break dendrites more efficiently, providing more space and path for liquid metal reflux, avoiding the problem of insufficient filling of intergranular liquid film, and reducing the tendency of hot cracking, but also improve element dispersion, phase transformation reaction and structural evolution process, and reduce defects such as element segregation and cracks.

[0018] 4. This invention provides a laser processing control system that can not only accurately realize modulated pulse laser processing based on scanning patterns and frequency adjustment, but also combine with an arc welding device to construct a new laser-arc composite welding system, so that the arc and modulated pulse laser work together on the workpiece to be processed, thereby improving the workpiece processing efficiency; it can also be combined with a powder spraying device to form a laser directional energy deposition system, effectively eliminating cracks in the deposition layer; thus expanding the application scenarios. Attached Figure Description

[0019] Figure 1 This is a typical pattern of laser scanning and a schematic diagram of the actual laser trajectory in an embodiment of the present invention; Figure 2 This is a schematic diagram of the actual motion trajectory of the modulated pulse laser in an embodiment of the present invention; Figure 3 This is a schematic diagram of a laser processing control system according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a laser-arc hybrid welding system according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a laser-directed energy deposition system according to an embodiment of the present invention.

[0020] The following reference numerals are used in the above figures: 1. Laser, 2. Transmission fiber, 3. Galvanometer focusing device, 4. Galvanometer lens group, 5. Galvanometer controller, 6. Motion mechanism, 7. Control cabinet, 8. Laser beam, 9. Scanning molten pool, 10. Workpiece being processed, 11. Laser scanning pattern, 12. Preset laser oscillation trajectory, 13. Modulated pulsed laser motion trajectory, 14. Weld seam, 15. Connecting fixture, 16. Arc welding torch, 17. Arc welding machine, 18. Laser directional energy deposition layer, 19. Powder feeder, 20. Powder feeder, 21. Protective gas cylinder. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The following description, in conjunction with a preferred embodiment, illustrates the content involved in the above embodiments.

[0023] Example 1 This invention provides a modulated pulsed laser processing method based on scanning patterns and frequency adjustment, comprising the following steps: S1, by setting the laser power, scanning frequency, scanning amplitude, and duration of each segment in different sections of the energy field, the laser power, scanning frequency, and scanning amplitude of the continuous laser are periodically alternating to form a modulated pulse laser; the modulation frequency and modulation duty cycle of the modulated pulse laser are determined according to the laser power, scanning frequency, and scanning amplitude of the continuous laser. S2, Generate a preset laser oscillation trajectory based on the preset laser scanning pattern, processing speed, and modulation frequency and modulation duty cycle of the modulated pulse laser; S3, the modulated pulsed laser acts on the workpiece to be processed according to the preset laser oscillation trajectory to form a molten pool, and laser processing is performed.

[0024] Optionally, the method may further include the following steps before step S1: Adjust the incident angle and defocusing amount of the continuous laser to make the laser act on the starting position of the workpiece to be processed.

[0025] In the embodiment of the present invention, by setting the laser scanning frequency, amplitude and duration of each segment in different sections, the scanning frequency, amplitude and power of the continuous laser are periodically alternating during the processing, inducing the molten pool to generate a periodic scanning stirring effect, thereby realizing pulse modulation of the energy input.

[0026] The laser processing procedure specifically includes the following steps: The first step is to adjust the spatial position of the laser beam so that it acts on the workpiece to be processed. The laser beam incident angle can be adjusted from -50° to 50°, with a preferred range of -10° to 10°; the defocusing amount can be adjusted from -30 to 30 mm, with a preferred range of -3 to 3 mm.

[0027] The second step involves setting the parameters of the continuous laser to produce a modulated pulsed laser with an effect similar to a pulsed laser. Specifically, by setting the laser power, scanning frequency, scanning amplitude, and duration of each segment within different energy field regions, the laser power, scanning frequency, and scanning amplitude of the continuous laser are periodically alternating, forming a modulated pulsed laser. Within adjacent segments, one or more parameters of the laser power, scanning frequency, and scanning amplitude change. For example, within a modulation cycle, a high energy density is obtained through an unscanned or low-frequency / small-amplitude scanning laser, serving as the peak energy region of the modulated pulsed laser; within adjacent segments, a low energy density is obtained through a high-frequency / large-amplitude scanning laser, serving as the valley energy region of the modulated pulsed laser. This modulation cycle repeats, periodically generating energy peaks and valleys, producing a waveform similar to a pulsed laser, thus transforming the uniformly energy-distributed continuous laser into a modulated pulsed laser.

[0028] The energy density of the modulated pulsed laser changes periodically in the laser processing direction. This means that the heat flow in the molten pool will form a new longitudinal surge or axial oscillation on the basis of the original radial scanning and rotating stirring of the laser, so that the scanning stirring changes from two-dimensional to three-dimensional, realizing three-dimensional, all-round orderly stirring of the heat flow in the molten pool. This can not only break dendrites more efficiently, providing more space and path for the molten metal to flow back, avoiding the problem of insufficient filling of the intergranular liquid film and reducing the tendency of hot cracking, but also improve element dispersion, as well as its phase transformation reaction and structural evolution process, reducing defects such as element segregation and cracks.

[0029] The third step involves setting the laser power and processing speed through the CNC system, and setting the scanning path of the modulated pulsed laser beam in the control software. This generates a preset laser oscillation trajectory.

[0030] like Figure 1 As shown, the displacement parameters of the modulated pulsed laser beam along the XYZ axes are determined. The preset laser scanning pattern can be any shape, including but not limited to broken lines, circles, figure-eights, infinity symbols, and inscribed double circles. Taking a commonly used circular scanning pattern as an example, the generated preset laser oscillation trajectory can be changed by altering parameters such as the local scanning frequency, local scanning amplitude, modulation frequency, and modulation duty cycle. In addition to individual control, the above control methods can also be simultaneously varied and combined to form composite control methods. Figure 1As shown, different laser scanning patterns 11 can be set to generate corresponding preset laser oscillation trajectories 12.

[0031] In this step, the scanning amplitude ranges from 0 to 20 mm, and in a preferred embodiment, it ranges from 0.3 to 2 mm; the scanning frequency ranges from 0 to 2000 Hz, and in a preferred embodiment, it ranges from 50 to 500 Hz; the modulation frequency ranges from 0 to 1000 Hz, and in a preferred embodiment, it ranges from 5 to 200 Hz; and the duty cycle ranges from 50% to 80%.

[0032] The fourth step involves applying the modulated pulsed laser to the workpiece according to the preset laser oscillation trajectory, thus initiating the laser processing. At this time, the laser beam performs high-speed oscillating scanning motion along a predetermined displacement trajectory. The high-energy-density laser melts the workpiece, forming a molten pool. The pulsed scanning behavior of the laser beam enhances the stirring effect of the molten pool, refining grains and suppressing defects such as weld porosity and cracks. In this step, the laser power ranges from 10 to 50 kW, with a preferred range of 3000 to 10000 W; the processing speed ranges from 0.1 to 30 m / min, with an optimized range of 2 to 6 m / min. When the modulated pulsed laser moves forward on the workpiece at a preset processing speed along different preset laser oscillation trajectories 12, the resulting modulated pulsed laser motion trajectory 13 is as follows: Figure 2 As shown.

[0033] In one specific embodiment, 304 stainless steel plates with a thickness of 8mm are selected for welding, and the welding method is laser welding.

[0034] In this embodiment, the operating platform is a six-axis robot system, the laser source is a 12kW fiber laser, and the laser beam is transmitted to the galvanometer through an optical fiber. The focal length of the galvanometer is 400mm.

[0035] The process parameters for modulated pulsed laser beam-arc hybrid welding in this embodiment are as follows: laser beam deflection angle is 0°, laser beam defocusing amount is -5mm, laser power is 9kW, welding speed is 1.5m / min; the scanning amplitude of the laser beam at the peak is 0.3mm, the scanning amplitude at the trough is 1.0mm, the oscillation frequency is 50Hz, the modulation frequency is 15Hz, and the duty cycle is 50%.

[0036] After welding using the above process parameters, the resulting weld 14 is aesthetically pleasing and smooth, without defects such as porosity or cracks. The required laser power is reduced by 30% compared to the existing scanning laser welding process, and the deformation is reduced by 12%.

[0037] This invention provides a modulated pulse laser processing method based on scanning pattern and frequency adjustment. By setting the laser power, scanning frequency, scanning amplitude, and duration of each segment in different energy field sections, the laser power, scanning frequency, and scanning amplitude of the continuous laser undergo periodic alternation, thereby generating a modulated pulse laser. A preset laser oscillation trajectory can be set according to the preset laser scanning pattern, processing speed, and laser parameters. Using a modulated pulse laser for laser processing of the workpiece maintains stable laser power throughout the process, effectively avoiding the frequent opening and closing of small holes caused by the periodic switching or large-range fluctuations of laser power in traditional modulated pulse modes, which induces defects such as spatter, edge biting, and porosity. By employing modulated pulsed lasers, the melting range can be increased through high-speed rotation of a large sweeping field with high-frequency valleys and large amplitudes, thus ordering the molten pool flow, enhancing the stirring ability of the molten pool, breaking dendrites, suppressing porosity, and improving the uniformity of precipitated phase distribution. Furthermore, the high energy density advantage of low-frequency peaks and small amplitudes improves energy utilization efficiency, achieving the same processing effect with reduced overall heat input, and avoiding problems such as molten pool instability, elemental burn-off, and thermal cracking caused by overheating. Compared with existing oscillating laser processing, this invention can reduce heat input by 10%-50%.

[0038] Example 2 like Figure 3 As shown, the present invention also provides a laser processing control system for performing a modulated pulse laser processing method based on scanning pattern and frequency adjustment as described in any one of Embodiment 1, comprising: a laser 1, a transmission optical fiber 2, a galvanometer focusing device 3, a galvanometer lens group 4, a galvanometer controller 5, a motion mechanism 6, a control cabinet 7, and a workpiece 10 to be processed; The control cabinet 7 is connected to the laser 1, the galvanometer controller 5, and the motion mechanism 6 respectively; the laser 1 is connected to the galvanometer focusing device 3 through the transmission optical fiber 2; the galvanometer controller 5 is connected to the galvanometer focusing device 3; The motion mechanism 6 is used to clamp the galvanometer focusing device 3 and drive the galvanometer focusing device 3 to move according to the control signal of the control cabinet 7, so that the laser beam acting on the workpiece to be processed moves at a preset processing speed. The galvanometer controller 5 is used to control the movement of the galvanometer lens group 4 in the galvanometer focusing device 3 according to preset parameters; the control cabinet 7 is used to control the power of the laser 1 according to preset parameters; the preset parameters include the laser power, scanning frequency, scanning amplitude and duration of each segment in different energy field segments, as well as the laser scanning pattern; The galvanometer assembly 4 is used to convert the continuous laser generated by the laser 1 into a modulated pulse laser that acts on the workpiece to be processed.

[0039] The working process of the system of this invention is as follows: Step 1: The galvanometer focusing device 3 is held by the motion mechanism 6. The spatial position of the laser beam 7 and its relative position with the workpiece 9 can be adjusted by the motion mechanism 6 to ensure that the laser acts on the workpiece to be processed.

[0040] Step 2: The laser power and welding speed are set through the control cabinet 7, while the galvanometer controller 5 sets the local scanning amplitude, frequency, modulation frequency, duty cycle, etc. of the oscillating laser beam 8 to modulate the laser beam to form an effect similar to a pulsed laser.

[0041] Step 3: Turn on laser 1 according to the above-mentioned set parameters to generate a laser beam and carry out the modulated pulse laser beam processing task. It acts on the workpiece to be processed to form a scanning molten pool 9. The preset laser oscillation trajectory 12 is a complex curve formed by the superposition of the micro-motion of laser beam 8 and the movement of motion mechanism 6.

[0042] This invention provides a laser processing control system for performing the modulated pulse laser processing method based on scanning pattern and frequency adjustment as described in any one of Embodiment 1, and has the same beneficial effects.

[0043] Example 3 The present invention also provides a laser-arc hybrid welding system, including an arc welding machine 17, an arc welding gun 16, a connecting fixture 15, and the laser processing control system described in Embodiment 2; The arc welding gun 16 is connected to the galvanometer focusing device 3 in the laser processing control system via the connecting clamp 15; The arc welding machine 17 is used to control the arc welding gun 16 to generate an electric arc, so that the electric arc and the modulated pulse laser generated in the laser processing control system work together on the workpiece to be processed.

[0044] Modulated pulsed laser-arc hybrid welding system, such as Figure 4 As shown, based on Embodiment 2, an arc welding machine 17, an arc welding gun 16, and a connecting fixture 15 are added.

[0045] This embodiment involves the welding of 5mm thick 6061 aluminum alloy flat plates using a laser-arc hybrid welding method.

[0046] In this embodiment, the operating platform is a six-axis robot system, the laser source is a 12000W fiber laser, the arc heat source is a 500A pulse digital control consumable electrode inert gas welding machine, and the laser beam is transmitted to the galvanometer through an optical fiber. The focal length of the galvanometer is 400mm.

[0047] The process parameters for modulated pulsed laser beam-arc hybrid welding in this embodiment are as follows: the angle between the laser beam and the arc welding gun is 55°, the laser-arc distance is 3mm, the laser beam defocusing amount is -2mm, the laser power is 4000W, the arc current is 200A, and the welding speed is 2m / min; the scanning amplitude of the laser beam at the peak is 0.3mm, the scanning amplitude at the trough is 1.2mm, the oscillation frequency is 300Hz, the modulation frequency is 10Hz, and the duty cycle is 50%.

[0048] After welding using the above process parameters (using 5087 aluminum-magnesium welding wire with a diameter of 1.2mm), the resulting weld 14 is aesthetically pleasing and full, without defects such as undercut, porosity, or cracks. The required laser power is reduced by 27% compared to the existing scanning laser-arc hybrid welding process, and the weld tensile strength is 275MPa, which is 25% higher than the existing laser-arc hybrid welding process.

[0049] Example 4 The present invention also provides a laser directional energy deposition system, including a powder feeding head 19, a powder feeder 20, and the laser processing control system described in Embodiment 2; The powder feeding head 19 is connected to the powder feeder 20; The powder feeding head 19 is installed below the galvanometer focusing device 3 in the laser processing control system, and is used to transport the powder in the powder feeder 20 to the molten pool area on the workpiece to be processed to form a deposition layer.

[0050] Laser-directed energy deposition system such as Figure 5 As shown, a powder feeding head 19 and a powder feeder 20 were added based on Embodiment 2.

[0051] Furthermore, in one embodiment, the laser directional energy deposition system also includes a protective gas cylinder 21 for protecting the powder feeder 20.

[0052] This embodiment describes laser-directed energy deposition of 2024 aluminum gold powder.

[0053] In this embodiment, the operating platform is a six-axis robot system, the laser source is a 6000W fiber laser, the laser beam is transmitted to the galvanometer through the optical fiber, the focal length of the galvanometer is 250mm, and a dual-cylinder automatic powder feeder and a four-channel coaxial powder feeding nozzle are used to feed aluminum powder.

[0054] The process parameters for modulated pulsed laser directional energy deposition in this embodiment are as follows: laser beam deflection angle is 0, laser beam defocusing amount is +10mm, laser power is 2000W, deposition speed is 1m / min; laser beam scanning amplitude at the peak is 1mm, scanning amplitude at the trough is 2mm, oscillation frequency is 500Hz, modulation frequency is 20Hz, and duty cycle is 50%.

[0055] After deposition using the above process parameters, the resulting deposition layer is uniform and smooth, and the porosity decreases from 3.3% in the non-scanning laser deposition method to below 1%. Furthermore, the metallurgical defects of cracks present in non-scanning laser energy deposition can be effectively eliminated by this invention. Correspondingly, the tensile strength increases from 250 MPa to 278 MPa, an improvement of 11%.

[0056] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A modulated pulse laser processing method based on scanning pattern and frequency adjustment, characterized in that, Includes the following steps: S1, by setting the laser power, scanning frequency, scanning amplitude, and duration of each segment in different sections of the energy field, the laser power, scanning frequency, and scanning amplitude of the continuous laser are periodically alternating to generate a modulated pulse laser; the modulation frequency and modulation duty cycle of the modulated pulse laser are determined according to the laser power, scanning frequency, and scanning amplitude of the continuous laser. S2, Generate a preset laser oscillation trajectory based on the preset laser scanning pattern, processing speed, and modulation frequency and modulation duty cycle of the modulated pulse laser; S3, the modulated pulsed laser acts on the workpiece to be processed according to the preset laser oscillation trajectory to form a molten pool, and laser processing is performed.

2. The modulated pulse laser processing method according to claim 1, characterized in that, The steps preceding step S1 also include: Adjust the incident angle and defocusing amount of the continuous laser to make the laser act on the starting position of the workpiece to be processed.

3. The modulated pulse laser processing method according to claim 2, characterized in that, The incident angle is adjustable from -50° to 50°; the defocusing amount is adjustable from -30 to 30 mm.

4. The modulated pulse laser processing method according to claim 1, characterized in that, The scanning frequency ranges from 0 to 2000 Hz; the scanning amplitude ranges from 0 to 20 mm; and the laser power ranges from 10 to 50 kW.

5. The modulated pulse laser processing method according to claim 1, characterized in that, The processing speed ranges from 0.1 to 30 m / min.

6. A laser processing control system for performing the modulated pulse laser processing method based on scanning pattern and frequency adjustment as described in any one of claims 1-5, characterized in that, include: Laser (1), transmission fiber (2), galvanometer focusing device (3), galvanometer lens group (4), galvanometer controller (5), motion mechanism (6), control cabinet (7) and workpiece to be processed (10). The control cabinet (7) is connected to the laser (1), the galvanometer controller (5) and the motion mechanism (6) respectively; the laser (1) is connected to the galvanometer focusing device (3) through the transmission optical fiber (2); the galvanometer controller (5) is connected to the galvanometer focusing device (3); The motion mechanism (6) is used to clamp the galvanometer focusing device (3) and drive the galvanometer focusing device (3) to move according to the control signal of the control cabinet (7) so that the laser beam acting on the workpiece to be processed moves at a preset processing speed. The galvanometer controller (5) is used to control the movement of the galvanometer lens group (4) in the galvanometer focusing device (3) according to preset parameters; the control cabinet (7) is used to control the power of the laser (1) according to preset parameters; the preset parameters include the laser power, scanning frequency, scanning amplitude and duration of each segment in different energy field segments, as well as the laser scanning pattern; The galvanometer assembly (4) is used to convert the continuous laser generated by the laser (1) into a modulated pulse laser that acts on the workpiece to be processed.

7. A laser-arc hybrid welding system, characterized in that, It includes an arc welding machine (17), an arc welding torch (16), a connecting fixture (15), and the laser processing control system as described in claim 6; The arc welding gun (16) is connected to the galvanometer focusing device (3) in the laser processing control system via the connecting clamp (15); The arc welding machine (17) is used to control the arc welding gun (16) to generate an arc, so that the arc and the modulated pulse laser generated in the laser processing control system work together on the workpiece to be processed.

8. A laser-directed energy deposition system, characterized in that, It includes a powder feeding head (19), a powder feeder (20), and the laser processing control system as described in claim 6; The powder feeding head (19) and the powder feeder (20) are connected; The powder feeding head (19) is installed below the galvanometer focusing device (3) in the laser processing control system and is used to transport the powder in the powder feeder (20) to the molten pool area on the workpiece to be processed to form a deposition layer.

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