Multiband laser polishing device and method based on polarization modulation

Abstract

The invention discloses a multiband laser polishing device and method based on polarization modulation, the multiband laser polishing device and method are suitable for surface polishing of anisotropic materials, the device comprises a sealed cabin, a multi-axial moving platform arranged in the sealed cabin, and a laser converter system arranged at the top of the sealed cabin; the multi-axial moving platform can enable a workpiece on the multi-axial moving platform to move and rotate along three axes; the laser converter system comprises a laser device bin located at the top of the sealed bin, a laser generator arranged in the laser device bin, a laser head converter connected with the laser device bin through a bearing, an infrared band laser head, an ultraviolet band laser head and a polarization modulation multi-band laser head, wherein the infrared band laser head, the ultraviolet band laser head and the polarization modulation multi-band laser head are fixed to the laser head converter and face the upper surface of the workpiece. The three laser heads are respectively connected with an infrared laser processor, an ultraviolet laser processor and a polarization modulation module which are arranged in the laser device bin; through the synergistic effect of multi-band laser, the smoother and more uniform workpiece surface effect is obtained, and efficient and low-damage polishing of complex curved surfaces and micropore structures is achieved.

Description

Technical Field

[0001] This invention relates to the field of laser surface treatment technology, and in particular to a multi-band laser polishing device and method based on polarization modulation, which is suitable for surface polishing of anisotropic materials, especially for high-quality surface treatment of materials such as metals, ceramics, and semiconductors. Background Technology

[0002] Surface polishing is a crucial step in product manufacturing, aiming to improve the dimensional and geometric accuracy of workpieces. Its main function is to reduce surface roughness, resulting in a bright, smooth surface that is more aesthetically pleasing. It also effectively enhances the corrosion and wear resistance of the material and helps it acquire special properties. Therefore, it has wide applications in mold making, aerospace, automotive, medical devices, and optoelectronics industries. High-quality and efficient polishing technology is of paramount importance to the manufacturing industry.

[0003] Laser polishing, as a green, environmentally friendly, flexible, efficient, intelligent, and reliable new polishing method, is more likely to meet the requirements of high efficiency and high precision compared with traditional polishing techniques. It is applicable to a variety of materials such as metals, ceramics, and glass. Traditional laser polishing techniques mostly use single-band or fixed-polarization lasers, suitable for isotropic materials (such as glass and metals). However, for anisotropic materials (such as crystals and composite materials), their optical and thermal properties vary with crystal orientation or structural direction, and traditional methods are prone to uneven polishing, surface damage, or low efficiency.

[0004] While polarized lasers are currently used in micromachining, they primarily focus on the effects of a single polarization state (such as linear polarization etching), lacking dynamic polarization modulation and multi-band synergistic polishing schemes for anisotropic materials. Therefore, it is necessary to develop a laser polishing device and method that can adapt to the anisotropy of materials. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a multi-band laser polishing device and method based on polarization modulation. Utilizing the characteristic that anisotropic materials respond differently to lasers with different polarizations, the invention achieves high-quality polishing of anisotropic materials by switching the polarization state of a multi-band laser head and adjusting the polarization combination. This improves the flatness and smoothness of the material surface, effectively solving the drawbacks and shortcomings of traditional laser polishing methods and meeting the needs of high-end manufacturing for processing anisotropic materials.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A multi-band laser polishing device based on polarization modulation includes a sealed chamber 14, a multi-axial moving platform disposed inside the sealed chamber 14, and a laser converter system disposed on the top of the sealed chamber 14.

[0008] The multi-axis moving platform enables the work panel 7 mounted thereon to move and rotate along the x-axis, y-axis, and z-axis, and the workpiece clamp 16 is mounted on the work panel 7.

[0009] The laser converter system includes a laser device compartment 2 located at the top of the sealed chamber 14, a laser generator disposed in the laser device compartment 2, a laser head converter 3 connected to the laser device compartment 2 via bearings, and an infrared laser head 4, an ultraviolet laser head 5, and a polarization-modulated multi-band laser head 6 fixed on the laser head converter 3. The infrared laser head 4, ultraviolet laser head 5, and polarization-modulated multi-band laser head 6 face the upper surface of the workpiece on the workpiece fixture 16 and are respectively connected to the infrared laser processor, the ultraviolet laser processor, and the polarization modulation module disposed in the laser device compartment 2.

[0010] The workpiece is an anisotropic material workpiece, such as a metal crystal, ceramic, semiconductor, or other material workpiece with special optical response characteristics.

[0011] The sealed chamber 14 is equipped with a laser control system on its outer side, which is connected to the laser sources and polarization modulation modules of the infrared laser head 4, the ultraviolet laser head 5, and the polarization modulation multi-band laser head 6. It can control the band switching and polarization state of the laser according to preset process parameters.

[0012] Preferably, the sealed chamber 14 is an argon-sealed chamber. Argon can create an inert physical and chemical environment to inhibit the oxidation reaction of metals. The argon-sealed chamber is equipped with a chamber pressure detection sensor and an oxygen concentration sensor. The chamber pressure detection sensor can maintain a dynamic airtight barrier and control the stability of argon coverage, while the oxygen concentration sensor ensures a chemically inert environment during the processing.

[0013] Preferably, the multi-axis moving platform includes two y-axis motion guide rails 10 fixed on the base, a y-axis motion guide rail slider 11 sliding along the two y-axis motion guide rails, an x-axis motion guide rail 8 integral with the y-axis motion guide rail slider, an x-axis motion guide rail slider 9 sliding along the x-axis motion guide rail 8, a z-axis motion guide rail 12 integral with the x-axis motion guide rail slider, a z-axis motion guide rail slider 13 sliding along the z-axis motion guide rail 12, and a work panel 7 connected to the z-axis motion guide rail slider 13 via a rotating disk 15. Multi-degree-of-freedom motion control enables precise all-around polishing of complex curved surfaces (such as edges and bevels).

[0014] Preferably, it also includes a base 1 located at the bottom of the sealed chamber 14 for easy movement; the base 1 is fixed to the sealed chamber 14 by bolts, and the laser device compartment 2 is tightly fitted to the sealed chamber 14 at the top of the sealed chamber to ensure that the sealed chamber 14 is sealed.

[0015] Preferably, the laser head converter 3 can rotate relative to each other along the axis, and the infrared band laser head 4, the ultraviolet band laser head 5, and the polarization modulation multi-band laser head 6 are evenly distributed around the circumference of the axis, which facilitates switching and adjusting the position.

[0016] Preferably, the workpiece fixture 16 has a protrusion below it that embeds into the groove of the work panel 7 to form a sliding pair, which ensures the workpiece remains stable during complex trajectory movements and avoids processing displacement.

[0017] The operating method of the polarization-modulated multi-band laser polishing device is characterized by the following steps:

[0018] Step 1: Open the door of the sealed chamber 14 and clamp the workpiece with the workpiece clamp 7 to ensure that the workpiece will not slide relative to the work panel 7 during the movement of the three-axis motion guide rail and the rotary disk 15.

[0019] Step 2: Adjust the angle of the laser head converter 3 to ensure that the processing areas of the infrared laser head 4, the ultraviolet laser head 5, and the polarization-modulated multi-band laser head 6 overlap and are within the range of the workpiece's upper surface.

[0020] Step 3: Adjust the positions of the x-axis motion guide slider 9, the y-axis motion guide slider 11, and the z-axis motion guide slider 13 so that the upper surface of the workpiece is located at the focal plane of the infrared laser head 4 and the ultraviolet laser head 5.

[0021] Step 4: Close the door of the sealed chamber 14 and open the argon filling switch to fill the sealed chamber 14 with argon as a protective gas;

[0022] Step 5: When the oxygen concentration drops to the specified range, turn off the argon gas filling switch and the exhaust switch at the same time to maintain an argon atmosphere in the sealed chamber.

[0023] Step 6: Start the laser generator in the laser device compartment 2, use the infrared band laser head 4 pulse mode, set its output power, laser scanning speed, pulse width, frequency parameters, and control the defocusing amount of the infrared band laser head 4 to pre-treat the upper surface of the workpiece to remove the oxide layer material on the workpiece surface that may affect the surface quality after polishing.

[0024] Step 7: Switch the infrared laser head 4 from pulse mode to continuous mode. According to the scanning speed relationship between infrared laser and ultraviolet laser, set the scanning speed of infrared laser head 4 and ultraviolet laser head 5 respectively through infrared laser processor and ultraviolet laser processor. At the same time, set the output power of infrared laser head 4 and ultraviolet laser head 5. First, use infrared laser head 4 for rough polishing, and then rotate laser head converter 3 to use ultraviolet laser head 5 for fine polishing.

[0025] Step 8: Adjust the positions of the x-axis motion guide slider 9 and the y-axis motion guide slider 11, and process different areas of the workpiece surface as in Step 7;

[0026] Step 9: Adjust the angle of the rotary disk 15 and the position of the slider 13 of the Z-axis motion guide rail, and process the inclined areas on both sides of the upper surface of the workpiece according to Step 7 and Step 8.

[0027] Step 10: After processing is completed, rotate the laser head converter 3 and readjust the position of the z-axis motion guide slider 13 so that the polarization modulation multi-band laser head 6 is facing the area of ​​the workpiece surface that needs further polishing, and so that the upper surface of the workpiece is located at the focal plane of the polarization modulation multi-band laser head 6.

[0028] Step 11: Set the laser power, pulse width, and repetition frequency parameters of the polarization modulation multi-band laser head 6 through the polarization modulation module;

[0029] Step 12: Use polarization-modulated multi-band laser head 6 to further polish the workpiece surface;

[0030] Step 13: As needed, adjust the relative position of the polarization modulation multi-band laser head 6 and the workpiece by adjusting the x-axis motion guide slider 9 and the y-axis motion guide slider 11, and continuously polish different areas of the workpiece to ensure that the entire workpiece surface is uniformly heated and strengthened.

[0031] Step 14: Adjust the angle of the rotary disk 15 and the position of the Z-motion guide slider 13, and process the inclined areas on both sides of the upper surface of the workpiece according to Step 13.

[0032] Step 15: After polishing is complete, turn off the laser generator in laser device chamber 2 and wait for the workpiece to cool to room temperature;

[0033] Step 16: Open the exhaust switch to release the argon gas from the sealed chamber;

[0034] Step 17: Level the rotating disk 15 and bring the positions of the x-axis motion guide slider 9, y-axis motion guide slider 11 and z-axis motion guide slider 13 to zero, while adjusting the laser head converter 3 to the initial angle.

[0035] Step 18: Open the workpiece fixture 16 and take out the workpiece that has undergone multi-band laser polishing treatment. Check the surface quality and strengthening effect of the workpiece.

[0036] Preferably, in step 6, the infrared laser head 4 has a high output power, which effectively ensures that the heating, vaporization and spraying of the impurity layer are completed in a very short time, achieving a highly efficient removal effect and preventing excessive heat conduction to the substrate and causing damage. In step 7, the infrared laser head 4 has a low output power, and the energy input is relatively smooth, ensuring the time required for the molten metal to level. The oxygen concentration in step 5 should be reduced to below 100 ppm to suppress the oxidation reaction of the high-temperature molten metal, thereby avoiding surface defects caused by oxidation.

[0037] Preferably, in step 6, the relationship between the defocusing amount of the infrared laser head 4 and the light spot is determined by the following formula:

[0038]

[0039] In the formula, D is the spot diameter, D0 is the waist spot diameter, and z is the defocusing amount of the infrared laser head. R Where λ is the Rayleigh length and λ is the laser wavelength;

[0040] In step 7, during continuous mode, the average energy density of the infrared laser head 4 is determined by the following formula:

[0041]

[0042] In the formula, P is the infrared laser power, and t is the time the laser spot stays on the workpiece surface. In continuous laser, t = D / v f A is the area of ​​the light spot, v f For scanning speed;

[0043] The scanning speed of the infrared laser head with 4 beams in continuous mode and the scanning speed of the ultraviolet laser head with 5 beams are determined by the following formulas:

[0044]

[0045]

[0046] According to formulas (4) and (5):

[0047]

[0048] In the formula, d is the distance from the center point of the laser head to the workpiece surface, and α is the angle between the laser head and the workpiece surface. The infrared laser head is in 4-beam continuous mode. Where s hy+z is half the side length of the processing area set at the focal plane of the infrared laser head 4, f is the distance from the infrared laser head 4 to the focal plane, y+z is the length of the processing area at the focal plane mapped onto the workpiece surface, v1 is the beam scanning speed of the ultraviolet laser head 5, v2 is the beam scanning speed of the infrared laser head 4, and d is the distance from the infrared laser head 4 to the focal plane. f This is the actual side length at the 4th focal plane of the infrared laser head.

[0049] Preferably, the infrared laser head 4 in step 7 has a beam wavelength of 1064nm. Infrared light in this band has a large penetration depth, which can penetrate deep into the material and is suitable for rapidly melting micron-level surface layers, efficiently eliminating macroscopic defects such as scratches and burrs, and improving surface smoothness. The ultraviolet laser head 5 in step 7 has a beam wavelength of 355nm. Ultraviolet light in this band has high photon energy (approximately 3.49eV), which exceeds the chemical bond energy of most metal / semiconductor materials. Therefore, it can directly break chemical bonds, achieve cold processing, and avoid the influence of thermal effects.

[0050] Preferably, in step 18, a comprehensive inspection is performed on the workpiece after multi-band laser polishing, including surface roughness inspection using a lever dial indicator and surface crack inspection using a surface analysis instrument.

[0051] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0052] 1) Due to the multi-band collaborative structure of infrared laser head 4, ultraviolet laser head 5 and polarization-modulated multi-band laser head 6, it can provide laser processing capabilities with multiple wavelengths and multiple polarization states for different material properties, realize the synergistic effect of rough polishing and fine polishing, and significantly improve the surface quality of anisotropic materials after polishing.

[0053] 2) Due to the combined structure of the multi-axis moving platform (including x / y / z axis motion guides and sliders) and the rotary disk 15, multi-degree-of-freedom motion control can achieve all-round precise polishing of complex curved surfaces (such as edges and inclined surfaces).

[0054] 3) Due to the argon-sealed chamber 14 and the chamber pressure detection sensor and oxygen concentration sensor installed inside, the oxygen concentration in the processing environment is precisely controlled below 100ppm, which can effectively suppress the oxidation of materials during the high-temperature polishing process.

[0055] 4) Due to the design of the work fixture 16 and the slide, the workpiece can be kept stable during complex trajectory movements, avoiding machining displacement.

[0056] 5) Due to the infrared laser energy density control based on formula (3) in the working method, the output power of 1064nm infrared coarse polishing can be precisely controlled, ensuring efficient material removal while avoiding surface cracks.

[0057] 6) Due to the synergy of the infrared laser and ultraviolet laser scanning speeds based on formula (6) in the working method, the surface roughness and crack rate can be optimized synergistically by coordinating the timing of infrared continuous mode rough polishing and ultraviolet fine polishing, combined with lever dial gauge detection. Attached Figure Description

[0058] Figure 1 This is a three-dimensional view of the multi-band laser polishing device based on polarization modulation according to the present invention.

[0059] Figure 2 This is a front view of the multi-band laser polishing device based on polarization modulation according to the present invention.

[0060] Figure 3 This is a side view of the multi-band laser polishing device based on polarization modulation according to the present invention.

[0061] Figure 4 This is a top view of the multi-band laser polishing device based on polarization modulation according to the present invention.

[0062] Figure 5 This is a flowchart illustrating the specific implementation steps of the device of the present invention. Detailed Implementation

[0063] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0064] Reference Figures 1 to 4 This invention discloses a polarization-modulated multi-band laser polishing device for polishing the surface of anisotropic materials, comprising a rectangular base 1 with a sufficiently large area to accommodate a sealed chamber 14. The sealed chamber 14 is mounted on the base 1 and secured around its perimeter by clamps. The base 1 and the sealed chamber 14 are bolted together, and the sealed chamber 14 is fixed to a laser device chamber 2. The sealed chamber 14 contains a chamber pressure sensor and an oxygen concentration sensor, and its outer wall is equipped with an argon gas filling switch and an exhaust switch.

[0065] Two y-axis motion guide rails 10 are provided on the base 1 inside the sealed chamber 14. The y-axis motion guide rails 10 are connected to the x-axis motion guide rails 8 through y-axis motion guide rail sliders 11, allowing the x-axis motion guide rails 8 to slide along the y-axis motion guide rails 10. The power is provided by the y-axis motion guide rail motor and transmitted by the transmission worm gear. The z-axis motion guide rail 12 is connected to the x-axis motion guide rails 8 through the x-axis motion guide rail sliders 9. The y-axis motion guide rails 10 are fixed to the base plate 1. The x-axis motion guide rails 8 and y-axis motion guide rail sliders 11 are fixedly connected and form a sliding pair with the y-axis motion guide rails 10 through the y-axis motion guide rail sliders 11 and 11. The z-axis motion guide rail 12 is fixedly connected to the x-axis motion guide rail sliders 9 and forms a sliding pair with the x-axis motion guide rails 8 through the x-axis motion guide rail sliders 9 and 8 through the x-axis motion guide rail sliders 9 and 8. The working panel 7 is fixedly connected to the z-axis motion guide rail sliders 13 by bolts. The rotary disk 15 is connected to the z-axis motion guide rail 12 via the z-axis motion guide rail slider 13, allowing the rotary disk to slide along the z-axis motion guide rail 12. The L-shaped plate is connected to the rotary disk 15 via a screw, allowing the L-shaped plate to rotate clockwise or counterclockwise about the y-axis motion guide rail 10. The L-shaped plate has a work panel 7, on which a workpiece clamp 16 is mounted. The workpiece clamp 16 is adjustable, and its maximum working size should be larger than the maximum size of the workpiece. The workpiece is placed horizontally on the work panel 7 and clamped by the workpiece clamp 16. The three-axis motion guide rail has a movement speed of up to 200 mm / s, a working accuracy of ±0.02 mm, a vertical load capacity of up to 30 kg, and a cross-sectional load capacity of up to 20 kg.

[0066] A laser converter system is installed on the sealed chamber 14. The laser converter system includes a vertically mounted laser device compartment 2 at the top of the sealed chamber 14, a laser head converter 3 connected to the laser device compartment 2, and an infrared laser head 4, an ultraviolet laser head 5, and a polarization-modulated multi-band laser head 6 fixed on the laser head converter 3. An infrared laser processor, an ultraviolet laser processor, and a polarization modulation module are installed inside the laser device compartment 2, respectively connected to the infrared laser head 4, the ultraviolet laser head 5, and the polarization-modulated multi-band laser head 6. A laser control system is located on the outside of the sealed chamber 14, connected to the laser sources and polarization modulation modules of the infrared laser head 4, the ultraviolet laser head 5, and the polarization-modulated multi-band laser head 6, and can control the band switching and polarization state of the laser according to preset process parameters. The laser device compartment 2 is connected to the laser head converter 3 and has built-in bearings, allowing it to rotate relative to the laser head converter 3 along its axis. The infrared laser head 4, the ultraviolet laser head 5, and the polarization-modulated multi-band laser head 6 are fixed to the laser head converter 3 and evenly distributed around the circumference of the axis.

[0067] Taking the processing of the upper surface of a 20mm×10mm×10mm prismatic metal crystal material triangular prism workpiece as an example, this invention provides a polarization-modulated multi-band laser polishing method for polishing anisotropic material surfaces, such as... Figure 5 As shown, it includes the following steps:

[0068] Step 1: Open the door of the sealed chamber 14 and clamp the workpiece with the workpiece clamp 16 to ensure that the workpiece will not slide relative to the work panel 7 during the movement of the three-axis motion guide rail and the rotary disk 15.

[0069] Step 2: Adjust the angle of the laser head converter 3 to ensure that the processing areas of the infrared laser head 4, the ultraviolet laser head 5, and the polarization-modulated multi-band laser head 6 overlap and are within the range of the workpiece's upper surface.

[0070] Step 3: Adjust the positions of the x-axis motion guide slider 9, the y-axis motion guide slider 11, and the z-axis motion guide slider 13 so that the upper surface of the workpiece is located at the focal plane of the infrared laser head 4 and the ultraviolet laser head 5.

[0071] Step 4: Close the door of the sealed chamber 14 and open the argon filling switch to fill the sealed chamber 14 with argon as a protective gas;

[0072] Step 5: When the oxygen concentration drops to the specified range, turn off the argon gas filling switch and the exhaust switch at the same time to maintain an argon atmosphere in the sealed chamber.

[0073] Step 6: Start the laser generator in the laser device compartment 2, use the infrared band laser head 4 pulse mode, set its output power, laser scanning speed, pulse width, frequency and other parameters, and control the defocusing amount of the infrared band laser head 4 to pre-treat the upper surface of the workpiece to remove the oxide layer and other substances on the workpiece surface that may affect the surface quality after polishing.

[0074] Step 7: Switch the infrared laser head 4 from pulse mode to continuous mode, set the scanning speed of the two lasers according to the scanning speed relationship between the infrared laser and the ultraviolet laser, and set the output power and other parameters of the two lasers. First, use the infrared laser head 4 for rough polishing, then rotate the laser head converter 3 and use the ultraviolet laser head 5 for fine polishing. The time control is completed by computer software.

[0075] Step 8: Adjust the positions of the x-axis motion guide slider 9 and the y-axis motion guide slider 11, and process different areas of the workpiece surface as in Step 7;

[0076] Step 9: Adjust the angle of the rotary disk 15 and the position of the slider 13 of the Z-axis motion guide rail, and process the inclined areas on both sides of the upper surface of the workpiece according to Step 7 and Step 8.

[0077] Step 10: After processing is completed, rotate the laser head converter 3 and readjust the position of the z-axis motion guide slider 13 so that the polarization modulation multi-band laser head 6 is facing the area of ​​the workpiece surface that needs further polishing, and so that the upper surface of the workpiece is located at the focal plane of the polarization modulation multi-band laser head 6.

[0078] Step 11: Set the laser wavelength, power, pulse width, and repetition frequency of the polarization-modulated multi-band laser head 6 through the polarization modulation module;

[0079] Step 12: Use polarization-modulated multi-band laser head 6 to further polish the workpiece surface;

[0080] Step 13: As needed, adjust the relative position of the polarization modulation multi-band laser head 6 and the workpiece by adjusting the x-axis motion guide slider 9 and the y-axis motion guide slider 11, and continuously polish different areas of the workpiece to ensure that the entire workpiece surface is uniformly heated and strengthened.

[0081] Step 14: Adjust the angle of the rotary disk 15 and the position of the Z-motion guide slider 13, and process the inclined areas on both sides of the upper surface of the workpiece according to Step 13.

[0082] Step 15: After polishing is complete, turn off the laser generator in laser device chamber 2 and wait for the workpiece to cool to room temperature;

[0083] Step 16: Open the exhaust switch to release the argon gas from the sealed chamber;

[0084] Step 17: Level the rotating disk 15 and bring the positions of the x-axis motion guide slider 9, y-axis motion guide slider 11 and z-axis motion guide slider 13 to zero, while adjusting the laser head converter 4 to the initial angle.

[0085] Step 18: Open the workpiece fixture 16 and take out the workpiece that has undergone multi-band laser polishing treatment. Check the surface quality and strengthening effect of the workpiece.

[0086] In step 7, the output power of the infrared laser head 4 is less than that in step 6. After pretreatment to remove surface impurities, rough polishing is performed to avoid damage to the workpiece.

[0087] In step 5, the oxygen concentration sensor reading should be reduced to below 100 ppm to avoid oxidation under the thermal effect of the laser.

[0088] In step 16, the oxygen concentration sensor reading should be restored to above 9000 ppm.

[0089] In step 6, the relationship between the defocusing amount of the infrared laser head 4 and the light spot is determined by the following formula:

[0090]

[0091]

[0092] In the formula, D is the spot diameter, D0 is the waist spot diameter, and z is the defocusing amount of the infrared laser head. R λ is the Rayleigh length, and λ is the laser wavelength.

[0093] In step 7, during continuous mode, the average energy density of the infrared laser head 4 is determined by the following formula:

[0094]

[0095] In the formula, P is the infrared laser power, and t is the time the laser spot stays on the sample surface. In continuous laser, t = D / v f A is the area of ​​the laser spot (in a Gaussian laser, the area of ​​the laser spot is A = πD). 2 / 4), v f This refers to the scanning speed.

[0096] The scanning speed of the infrared laser head with 4 beams in continuous mode and the scanning speed of the ultraviolet laser head with 5 beams are determined by the following formulas:

[0097]

[0098] According to formulas (4) and (5):

[0099]

[0100] In the formula, d is the distance from the center point of the laser head to the workpiece surface, and α is the angle between the laser head and the workpiece surface. The infrared laser head is in 4-beam continuous mode. Where s h y+z is half the side length of the processing area set at the focal plane of the infrared laser head 4, f is the distance from the infrared laser head 4 to the focal plane, y+z is the length of the processing area at the focal plane mapped onto the workpiece surface, v1 is the beam scanning speed of the ultraviolet laser head 5, v2 is the beam scanning speed of the infrared laser head 4, and d is the distance from the infrared laser head 4 to the focal plane. f This is the actual side length at the 4th focal plane of the infrared laser head.

[0101] In step 7, the infrared laser head 4 has a beam wavelength of 1064nm, and the ultraviolet laser head 5 has a beam wavelength of 355nm.

[0102] In step 18, a comprehensive inspection is carried out on the entire workpiece after multi-band laser polishing, including surface roughness inspection using equipment such as a lever dial indicator, and surface crack detection using surface analysis instruments.

[0103] A multi-band laser polishing device and method based on polarization modulation innovatively employs simultaneous multi-band laser processing, covering infrared, ultraviolet, and other suitable bands, compared to traditional laser processing and polishing systems. Combined with polarization modulation technology, the laser polarization state is precisely controlled based on parameter ranges determined by anisotropic polarization analysis, achieving synergistic effects of multiple bands and multiple polarization states. Each band of laser performs its specific function and works synergistically: some bands efficiently remove oxide layers, while others are used for fine surface reconstruction. This synergistic effect of multiple bands achieves precise polishing and secondary reconstruction of the workpiece surface, significantly improving the polished surface quality, greatly enhancing the material's utilization of laser energy, and avoiding energy loss and laser damage risks. By rationally modulating the laser to polish anisotropic materials in different directions, high-precision surface polishing can be achieved. This polarization modulation technology enables the device and method to adapt to the differences in physical properties of anisotropic materials in different directions, fundamentally solving the problem of poor adaptability of traditional polishing methods to anisotropic materials. Combining the robustness of continuous laser and a controllable moving four-axis substrate platform, the device and method of this invention can perform surface polishing of workpieces with complex curvature. By adjusting the polarization parameters and processing parameters of multi-band lasers in real time, synchronous, large-format processing is achieved. For areas with special curvature requirements (such as curved edges), the material removal depth and heat-affected zone can be precisely controlled. This enables the surface polishing of more complex curved surfaces such as engine turbine blades, worm gears, and large-curvature molds, further increasing the types of materials processed and polishing efficiency, and broadening its market applications.

[0104] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A multi-band laser polishing device based on polarization modulation, characterized in that: Includes a sealed chamber (14), a multi-axial moving platform disposed within the sealed chamber (14), and a laser converter system disposed on top of the sealed chamber (14); The multi-axis moving platform enables the work panel (7) mounted thereon to move and rotate along the x-axis, y-axis, and z-axis, and the workpiece fixture (16) is mounted on the work panel (7); The laser converter system includes a laser device compartment (2) located at the top of the sealed chamber (14), a laser generator set inside the laser device compartment (2), a laser head converter (3) connected to the laser device compartment (2) via bearings, and an infrared laser head (4), an ultraviolet laser head (5), and a polarization-modulated multi-band laser head (6) fixed on the laser head converter (3). The infrared laser head (4), the ultraviolet laser head (5), and the polarization-modulated multi-band laser head (6) face the upper surface of the workpiece on the workpiece fixture (16) and are respectively connected to the infrared laser processor, the ultraviolet laser processor, and the polarization modulation module set inside the laser device compartment (2). The workpiece is an anisotropic material workpiece; The sealed chamber (14) is equipped with a laser control system on its outside, which is connected to the laser source and polarization modulation module of the infrared laser head (4), the ultraviolet laser head (5), and the polarization modulation multi-band laser head (6). It can control the band switching and polarization state of the laser according to the preset process parameters.

2. The multi-band laser polishing device based on polarization modulation according to claim 1, characterized in that: The sealed chamber (14) is an argon-sealed chamber, which is equipped with a chamber pressure detection sensor and an oxygen concentration sensor.

3. The multi-band laser polishing device based on polarization modulation according to claim 1, characterized in that: The multi-axis moving platform includes two y-axis motion guide rails (10) fixed on the base, a y-axis motion guide rail slider (11) that slides along the two y-axis motion guide rails, an x-axis motion guide rail (8) that is integral with the y-axis motion guide rail slider, an x-axis motion guide rail slider (9) that slides along the x-axis motion guide rail (8), a z-axis motion guide rail (12) that is integral with the x-axis motion guide rail slider, a z-axis motion guide rail slider (13) that slides along the z-axis motion guide rail (12), and a work panel (7) that is connected to the z-axis motion guide rail slider (13) via a rotating disk (15).

4. The multi-band laser polishing device based on polarization modulation according to claim 1, characterized in that: It also includes a base (1) set at the bottom of the sealed chamber (14), the base (1) being fixed to the sealed chamber (14) by bolts, and the laser device compartment (2) being tightly fitted to the sealed chamber (14) at the top of the sealed chamber; The laser head converter (3) can rotate relative to each other along the axis, and the infrared laser head (4), the ultraviolet laser head (5), and the polarization-modulated multi-band laser head (6) are evenly distributed around the circumference of the axis.

5. The multi-band laser polishing device based on polarization modulation according to claim 1, characterized in that: The workpiece fixture (16) has a protrusion that is embedded in the groove of the work panel (7) to form a sliding pair.

6. The operating method of the multi-band laser polishing apparatus based on polarization modulation according to any one of claims 1 to 5, characterized in that: Includes the following steps: Step 1: Open the sealed chamber (14) door and clamp the workpiece with the workpiece clamp (7) to ensure that the workpiece will not slide relative to the work panel (7) during the movement of the three-axis motion guide rail and the rotary disk (15); Step 2: Adjust the angle of the laser head converter (3) to ensure that the processing areas of the infrared laser head (4), the ultraviolet laser head (5) and the polarization-modulated multi-band laser head (6) overlap and are within the range of the workpiece surface. Step 3: Adjust the positions of the x-axis motion guide slider (9), y-axis motion guide slider (11) and z-axis motion guide slider (13) so that the upper surface of the workpiece is located at the focal plane of the infrared laser head (4) and the ultraviolet laser head (5); Step 4: Close the door of the sealed chamber (14) and open the argon filling switch to fill the sealed chamber (14) with argon as a protective gas; Step 5: When the oxygen concentration drops to the specified range, turn off the argon gas filling switch and the exhaust switch at the same time to maintain an argon atmosphere in the sealed chamber. Step 6: Start the laser generator in the laser device compartment (2), use the infrared band laser head (4) pulse mode, set its output power, laser scanning speed, pulse width, frequency parameters, and control the defocusing amount of the infrared band laser head (4) to pre-treat the upper surface of the workpiece to remove the oxide layer material on the workpiece surface that is likely to affect the surface quality after polishing. Step 7: Switch the infrared laser head (4) from pulse mode to continuous mode. According to the scanning speed relationship between infrared laser and ultraviolet laser, set the scanning speed of the infrared laser head (4) and the ultraviolet laser head (5) respectively through the infrared laser processor and the ultraviolet laser processor. At the same time, set the output power of the infrared laser head (4) and the ultraviolet laser head (5). First, use the infrared laser head (4) for rough polishing, and then rotate the laser head converter (3) to use the ultraviolet laser head (5) for fine polishing. Step 8: Adjust the positions of the x-axis motion guide slider (9) and the y-axis motion guide slider (11), and process different areas of the workpiece surface according to Step 7; Step 9: Adjust the angle of the rotary disk (15) and the position of the slider (13) of the z-axis motion guide rail, and process the inclined areas on both sides of the upper surface of the workpiece according to Step 7 and Step 8; Step 10: After processing, rotate the laser head converter (3) and readjust the position of the z-axis motion guide slider (13) so that the polarization modulation multi-band laser head (6) is facing the area of ​​the workpiece surface that needs further polishing, and so that the upper surface of the workpiece is located at the focal plane of the polarization modulation multi-band laser head (6). Step 11: Set the laser power, pulse width and repetition frequency parameters of the polarization modulation multi-band laser head (6) through the polarization modulation module; Step 12: Use a polarization-modulated multi-band laser head (6) to further polish the surface of the workpiece; Step 13: As needed, adjust the relative position of the polarization modulation multi-band laser head (6) and the workpiece by adjusting the x-axis motion guide slider (9) and the y-axis motion guide slider (11) to continuously polish different areas of the workpiece to ensure that the entire workpiece surface is uniformly heated and strengthened. Step 14: Adjust the angle of the rotary disk (15) and the position of the Z-motion guide slider (13), and process the inclined areas on both sides of the upper surface of the workpiece according to Step 13; Step 15: After polishing is completed, turn off the laser generator in the laser device chamber (2) and wait for the workpiece to cool to room temperature; Step 16: Open the exhaust switch to release the argon gas from the sealed chamber; Step 17: Level the rotating disk (15) and bring the positions of the x-axis motion guide slider (9), y-axis motion guide slider (11) and z-axis motion guide slider (13) to zero, while adjusting the laser head converter (3) to the initial angle. Step 18: Open the workpiece fixture (16) and take out the workpiece that has been treated with multi-band laser polishing. Check the surface quality and strengthening effect of the workpiece.

7. The working method according to claim 6, characterized in that: In step 7, the output power of the infrared laser head (4) is less than that in step 6; the oxygen concentration value in step 5 should be reduced to below 100 ppm.

8. The working method according to claim 6, characterized in that: In step 6, the relationship between the defocusing amount of the infrared laser head (4) and the light spot is determined by the following formula: In the formula, D is the spot diameter, D0 is the waist spot diameter, and z is the defocusing amount of the infrared laser head. R Where λ is the Rayleigh length and λ is the laser wavelength; In step 7, in continuous mode, the average energy density of the infrared laser head (4) is determined by the following formula: In the formula, P is the infrared laser power, and t is the time the laser spot stays on the workpiece surface. In continuous laser, t = D / v f A is the area of ​​the light spot, v f For scanning speed; The scanning speed of the infrared laser head (4) in continuous mode and the scanning speed of the ultraviolet laser head (5) are determined by the following formulas: According to formulas (4) and (5): In the formula, d is the distance from the center point of the laser head to the surface of the workpiece, α is the angle between the laser head and the surface of the workpiece, and the infrared laser head (4) in continuous beam mode Where s h y+z is half the side length of the processing area set at the focal plane of the infrared laser head (4), f is the distance from the infrared laser head (4) to the focal plane, y+z is the length of the processing area at the focal plane mapped onto the workpiece surface, v1 is the beam scanning speed of the ultraviolet laser head (5), v2 is the beam scanning speed of the infrared laser head (4), and d f This is the actual side length of the focal plane of the infrared laser head (4).

9. The working method according to claim 6, characterized in that: The infrared laser head (4) in step 7 has a beam wavelength of 1064nm, and the ultraviolet laser head (5) has a beam wavelength of 355nm.

10. The working method according to claim 6, characterized in that: In step 18, a comprehensive inspection is carried out on the workpiece after multi-band laser polishing, including surface roughness inspection using a lever dial indicator and surface crack detection using a surface analysis instrument.

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