Laser polishing device and debugging method thereof for aluminum alloy highlight polishing

Abstract

The invention discloses a laser polishing device and a debugging method thereof for aluminum alloy highlight polishing, and relates to the technical field of laser polishing. The laser polishing device comprises an optical fiber laser, a lifting mechanism, a laser machining assembly and a machining platform. The laser processing assembly comprises a laser light emitting head, a beam expander, a DOE and a galvanometer assembly. The laser polishing device is combined with a debugging method of the laser polishing device, so that the roughness of the laser high-brightness polished surface of the aluminum alloy can be reduced to 0.4 mu m or below, and the polishing brightness can be improved to 400-650 GU.

Description

Technical Field

[0001] The invention relates to the technical field of laser polishing, and in particular to a laser polishing device and a debugging method thereof for performing highlight polishing of aluminum alloy. Background Art

[0002] Aluminum alloy has the advantages of high strength, light weight, good electrical and thermal conductivity, excellent processing performance, good coloring performance, and a wear-resistant surface layer after anodizing. It is widely used in the fields of construction, transportation, aerospace, medical treatment, 3C, communications, and electronic products. As a high-quality structural and appearance material, aluminum alloy has a variety of structures, a variety of processing methods, and colorful appearance effects. With exquisite LOGO and surface decorative patterns, it can further enhance the grade and recognition of the product.

[0003] Although printing LOGO is simple to operate, the disadvantage of easy erasure determines that the LOGO has a short retention time; the process of mounting LOGO is complicated, requiring a variety of auxiliary equipment and processes, and the cost is relatively high; sandblasting LOGO requires the production of various templates, which can only be completed before anodizing, and its processing effect has great uncertainty, which is not conducive to small batches of multiple varieties, customized complex patterns and rapid product iteration. Laser engraving LOGO and surface decoration patterns are convenient and flexible, can process complex patterns, and can still be processed after anodizing, which is an excellent solution.

[0004] In recent years, the popular laser highlight polishing has been widely adopted by many manufacturers and products, such as DELL notebooks, Samsung mobile phones, electronic cigarettes, etc. However, with the improvement of product technology and customer experience requirements, the original polishing effect has gradually failed to meet the needs in terms of fineness and brightness. For example, the Chinese patent with publication number CN113458611 A discloses a laser marking method and device for high-gloss processing of aluminum alloys, which is actually a common application of laser marking machines, and the conclusions output are also qualitative rather than quantitative conclusions. By reproducing its structure and parameters, it is shown that: ① The surface roughness (0.6um) and brightness index (200GU) that can be achieved after laser laser engraving are relatively low; ② The entire process lacks data analysis and optimization process; ③ The process has greater uncertainty; ④ Especially when changing materials, the window parameters cannot be found quickly, and a long time of exploration is required, which is not conducive to the rapid switching of products. Summary of the invention

[0005] The laser polishing device and debugging method of the present invention have two main objectives: one is to use laser scanning to break the anodized layer on the surface of the aluminum alloy, expose the aluminum body, and reduce the roughness of the surface of the aluminum body; the other is to scan a higher brightness on the aluminum body with a smaller roughness.

[0006] To achieve the above-mentioned purpose, the present invention provides a laser polishing device for reducing the surface roughness of aluminum alloy after laser polishing and improving the polishing brightness, and a debugging method for high-brightness polishing that can adapt to the rapid switching of various aluminum alloy materials. The laser polishing device has strong logic and reproducibility. The laser polishing device combined with its debugging method can reduce the surface roughness of aluminum alloy laser high-brightness polishing to below 0.4um and increase the polishing brightness to 400-650GU. The specific implementation plan is as follows.

[0007] Provided is a laser polishing device, comprising an optical fiber laser, a lifting mechanism, a laser processing component and a processing platform; the laser processing component comprises a laser light output head, a beam expander, a DOE and a galvanometer component; the optical fiber laser can modulate two modes, pulse laser and continuous laser, and the laser light output head outputs Gaussian laser; the Gaussian laser is sequentially expanded, shaped, scanned and focused by the beam expander, DOE and galvanometer component and then irradiated onto the processing platform; the laser processing component is arranged on the lifting mechanism, and the lifting mechanism is used to adjust the up and down movement of the laser processing component; the processing platform is located below the galvanometer component.

[0008] Further, the fiber laser is a fiber infrared MOPA single-mode laser. In some specific embodiments, the fiber laser is a 50-500W fiber laser, preferably a 200W fiber laser, but not limited to 200W.

[0009] In some specific embodiments, the focal length of the galvanometer is 100-260 mm, such as the commonly used 100 mm, 160 mm, 200 mm, 254 mm, etc., and the preferred focal length is 160 mm.

[0010] Furthermore, the laser polishing device also includes a base; the lifting mechanism and the processing platform are arranged on the base.

[0011] The above-mentioned laser polishing device is used for the debugging method of aluminum alloy highlight polishing, which is characterized by comprising the following steps: Step 1: breaking the anodized layer

[0012] Step 11: Detect the thickness of the oxide layer;

[0013] Step 12 Determine the anode breaking laser parameters

[0014] S121 Focusing: placing the aluminum alloy sample on the processing platform, and adjusting the lifting mechanism to move the laser processing assembly to the front focus coordinate or the back focus coordinate;

[0015] S122 frequency setting: refer to the laser waveform diagram and set the frequency F corresponding to the highest power;

[0016] S123 sets the pulse width: refer to the laser parameter table to set the pulse width PW corresponding to the frequency F;

[0017] S124 engraved lines: Set the scanning speed to any value between 100-500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% in sequence, with 20 engraved lines;

[0018] S125 detection: measure the line width and depth of each engraved line in turn;

[0019] S126 determines the line width and power: first, select the lines whose line width does not change and have no heat-affected zone, and then select the lines whose line depth just exceeds the thickness of the oxide layer. The line width and power corresponding to the lines are the optimal line width D1 and power W1;

[0020] Step 13 Determine the scanning parameters

[0021] S131 Determine the filling spacing: Determine the filling spacing to be D1 / 2;

[0022] S132 determines the scanning speed: assuming that the spot diameter is D1, the laser frequency is F, the scanning speed is V, and the overlap ratio is R; the overlap ratio R = 1-V / D1*F, R ≥ 80%, and the scanning speed V = (1-R)*D1*F is determined by calculation;

[0023] S133 determines the switch light delay: the switch light delay setting value is 0-100ms;

[0024] S134 determines the filling pattern: selects parallel line filling;

[0025] S135 determines the filling direction: selects 0 degrees, and fills in a bow shape;

[0026] S136 Sample production: According to the parameters set in S131-S136, several 25*25mm samples are produced for the next step, Step 14 test;

[0027] Step 14 Second Scan

[0028] S141 determines the secondary scanning line width and power: the other parameters mentioned above remain unchanged, and the filling distance is set to be equal to D1 / 2, D1 / 2±0.005mm, D1 / 2±0.01mm, D1 / 2±0.015mm, respectively, and the laser power is set to be equal to W1 / 2, W1 / 2±5%, W1 / 2±10%, and the filling direction is 90 degrees, and the filling is in a bow shape. Take a piece of the sample of S136 and make a 5*5mm small sample on the sample; use a microscope to detect the roughness of the small sample, and determine that the filling distance corresponding to the small sample with the lowest roughness is the secondary scanning line width D2, and the corresponding laser power is the secondary scanning power W2;

[0029] S142 Sample preparation: According to the secondary scanning line width D2 and secondary scanning power W2 parameters determined in S141, perform secondary scanning on the remaining samples obtained in S136 to prepare 25*25mm samples for the next step Step 2 test;

[0030] Step 2 Flattening of the aluminum body

[0031] S21 Focusing: Adjust the lifting mechanism to move the laser processing assembly to the middle position between the front focus coordinate and the back focus coordinate;

[0032] S22 marking line: Set the pulse width of the fiber laser to 1ns, continuous laser mode; set the scanning speed to any value between 100-500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 20 marking lines;

[0033] S23 detection: measure the line width and depth of each engraved line in turn;

[0034] S24 Preliminary determination of line width and power: Select the lines that are completely melted, the width does not increase, and there is no heat-affected zone, and then select the lines with smooth surfaces and no explosion points. The line width and power corresponding to the lines are the preliminary line width D and power W;

[0035] S25: Make small samples: keep the scanning speed set in step S22 unchanged, set the filling spacing to D, D / 2±0.005mm, D / 2±0.01mm, D / 2±0.015mm, the power to W, W±5% and W±10%, the filling mode to grid, and make 5*5mm small samples on the samples obtained in S142;

[0036] S26 Confirm parameters: Use a confocal microscope to detect the samples, and select the sample with the lowest roughness. The corresponding filling spacing and power parameters are the optimal parameters D3 and W3;

[0037] S27 Sample preparation: According to the optimal parameters D3 and W3 confirmed in S26, a 25*25mm aluminum flattened sample is prepared on the remaining samples obtained in S142 for the next step, Step 3 test;

[0038] Step 3 Laser highlight polishing

[0039] S31 Focusing: Take a piece of S27 sample and place it on the processing platform, adjust the lifting mechanism to move the laser processing component to the front focus coordinate or the back focus coordinate;

[0040] S32 one polishing: set the pulse width to PW, set the scanning speed to any value between 100-500mm / s, the filling spacing to D1 / 2, the filling mode to bow, and the filling direction to 0 degrees; set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or until the scanning burst point, and make 5*5 polishing samples ≤20 in sequence;

[0041] S33 detection:

[0042] S331 Observation: Observe and examine the samples using a confocal microscope, and select several samples with relatively low roughness;

[0043] S332 gloss measurement: Use a gloss meter to measure the selected samples. The power corresponding to the sample with the largest GU value is the best first-throw power W4;

[0044] S34: Preparation of medium sample: take more pieces of S27 sample, set the power to W4, and make 25*25mm medium sample on S27 sample;

[0045] S35 Second polishing: Set the scanning speed to be the same as step S32, the filling distances are D1 / 2, D1 / 2±0.005mm, D1 / 2±0.01mm, D1 / 2±0.015mm respectively, the filling mode is bow, the filling direction is 90 degrees, the power is 2*W4, 2*W4±5%, 2*W4±10% respectively, and make 5*5mm polishing samples on the medium sample in sequence;

[0046] S36 confirms the parameters:

[0047] S361 Observation: Observe and examine the polished samples using a confocal microscope, and select several samples with relatively low roughness;

[0048] S362 gloss measurement: Use a gloss meter to measure the selected samples. The filling distance and power corresponding to the sample with the largest GU value are the optimal filling distance parameter D5 and the optimal power parameter W5;

[0049] S37 Sample production: Produce multiple regular samples according to the above S11-S36 process, check the reproducibility of the parameters, and archive the samples.

[0050] Preferably, the Step 11 of detecting the oxide layer thickness is specifically as follows: using an eddy current film thickness tester to detect the oxide layer thickness, with at least five detection points distributed around the periphery and center of the workpiece, and taking the maximum detection thickness as the oxide layer thickness.

[0051] Preferably, in the Step 21, the lifting mechanism is adjusted to move the laser processing component to the front focus coordinate or the back focus coordinate, specifically: the scanning speed of the fiber laser is set to any value between 1-10 mm / s, and the laser is emitted for continuous scanning, and the lifting mechanism is adjusted at the same time to drive the laser processing component to continuously descend from the highest position, and the coordinate point of the laser processing component when the laser flashes most intensely on the sample for the first time is recorded as the back focus coordinate, and the coordinate point of the laser processing component when the laser flashes most intensely on the sample for the second time is recorded as the front focus coordinate.

[0052] Preferably, in said S26, before using the confocal microscope to detect the sample, it also includes using a multimeter The test sample is qualified if it makes a "beeping" sound during short circuit test.

[0053] Preferably, after S362, the method further includes S363 short circuit measurement: using a multimeter The resistance of the sample is infinite and it is qualified if there is no "beeping" sound.

[0054] The above-mentioned debugging method of the present invention first removes the anodized layer by pulsed laser scanning, controls the line width, depth and heat-affected zone of the anodized layer, and exposes the aluminum body; then uses DOE-homogenized low-power continuous laser scanning to remove the aluminum body of the oxide layer, thereby obtaining a lower surface roughness; finally, uses non-DOE-homogenized high-power continuous laser scanning to melt and level the tiny bumps on the surface of the substrate, and an oxidation reaction occurs again to generate a high-brightness oxide layer surface.

[0055] The laser polishing device and its debugging method of the present invention are mainly used for polishing the surface of aluminum alloy after anodization. The applicable alloy materials include 1 series pure aluminum series, 5 series aluminum-magnesium alloy series, 6 series aluminum-magnesium-silicon alloy series, and 7 series aluminum-zinc alloy series; the applicable surface polishing includes untreated surface and anodized surface, and the anodized surface further includes natural color anodizing, black anodizing, color anodizing, sandblasting anodizing, hard low-temperature anodizing, etc., which are applicable to most aluminum alloy appearance products on the market. The debugging method is applicable to the switching production between the above-mentioned different alloy materials, and quickly finds out the polishing process window parameters of the alloy material, so that the polished surface roughness of the alloy material can reach below 0.4um, and the surface finish can reach above 400GU, which is much higher than the highest brightness level on the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0057] Figure 1 Schematic diagram of a laser polishing device according to an embodiment of the present invention.

[0058] Figure 2 Schematic diagram of the working mode principle of the DOE element in an embodiment of the present invention.

[0059] Figure 3 This is a process diagram of a method for debugging aluminum alloy highlight polishing using a laser polishing device according to an embodiment of the present invention.

[0060] Figure 4 This is a process flow chart of removing the anodized layer in Step 1 of an embodiment of the present invention.

[0061] Figure 5 This is a process flow chart of flattening the aluminum body in Step 2 of an embodiment of the present invention.

[0062] Figure 6 This is a process flow chart of laser highlight polishing in Step 3 of an embodiment of the present invention.

[0063] Figure 7 This is a diagram showing the polishing effects of the laser polishing device under different debugging parameters according to an embodiment of the present invention.

[0064] Description of the symbols in the figure:

[0065] 10-marble base, 11-processing platform, 12-aluminum alloy sample, 20-laser processing group, 21-fiber laser, 22-laser light output head, 23-beam expander, 24-lifting mechanism, 25-DOE, 26-galvanometer assembly, 100-Gaussian laser, 101-Gaussian laser, 102-flat-top laser, 103-processing beam. DETAILED DESCRIPTION

[0066] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Example

[0068] See also Figure 1 The laser polishing device shown includes a marble base 10, a processing platform 11, an aluminum alloy sample 12, a fiber laser 21, a laser light output head 22, a beam expander 23, a lifting mechanism 24, a DOE 25, and a galvanometer assembly 26; the laser light output head 22, the beam expander 23, the DOE 25, and the galvanometer assembly 26 constitute a laser processing assembly 20.

[0069] The fiber laser 21 is a 200W fiber infrared MOPA single-mode laser, which can be modulated into two modes: pulsed laser and continuous laser, and outputs Gaussian laser through the laser output head 22; the Gaussian laser 100 output by the laser output head 22 is expanded by the beam expander 23 into Gaussian laser 101 with a larger beam diameter and lower power density to reduce the damage to the DOE 25; the Gaussian laser 101 can be shaped into flat-top laser 102 with uniform energy after passing through the DOE 25, and the flat-top laser 102 can output a processing beam 103 with extremely high energy density after being scanned and focused by the galvanometer assembly 26, and the processing beam 103 can complete the processing of various patterns on the aluminum alloy surface. In this embodiment, the focal length of the galvanometer is 160mm.

[0070] The laser processing assembly 20 is arranged on the lifting mechanism 24, and the lifting mechanism 24 can adjust the laser processing assembly 20 to lift along the Z-axis direction (i.e., move up and down), which is used to adjust the vertical positions of the focal plane and the homogenization plane to ensure that the processing surface is located on the surface of the aluminum alloy sample 12. The lifting mechanism 24 and the processing platform 11 are both installed and fixed on the marble base 10, and the processing platform 11 is located below the galvanometer assembly 26.

[0071] The working mode principle of the DOE element is as Figure 2 shown, Figure 2 In the figure, 1 is the front focus of the DOE, 3 is the rear focus of the DOE, and the position shown as 2 is the homogenization plane of the DOE. The laser polishing device in this embodiment applies two working modes of the DOE element: homogenization and positive focus (either the front focus or the rear focus). By lifting the lifting mechanism 24, the laser processing assembly 20 is adjusted to move to the homogenization plane and the positive focus (the front focus or the rear focus). Specifically: the fiber laser is set to a scanning speed of 10mm / s, emits laser for continuous scanning, and at the same time adjusts the lifting mechanism to drive the laser processing assembly to continuously descend from the highest position, records the coordinate point of the laser processing assembly when the laser flashes most strongly for the first time on the sample as the rear focus coordinate, records the coordinate point of the laser processing assembly when the laser flashes most strongly for the second time on the sample as the front focus coordinate, and the middle position between the rear focus coordinate and the front focus coordinate is the homogenization plane.

[0072] The debugging method for high-brightness polishing of aluminum alloy (5-series aluminum-magnesium alloy series) by the above laser polishing device is as Figure 3 shown, and it is divided into three major steps.

[0073] Step1: Remove the anodic oxidation layer;

[0074] Step2: Flatten the aluminum material body;

[0075] Step3: Laser high-brightness polishing.

[0076] The specific implementation steps are as follows:

[0077] Step 1: Remove the anodized layer. The process is as follows: Figure 4 As shown:

[0078] Step 11: Detect the oxide layer thickness: Use an eddy current film thickness tester to detect the oxide layer thickness. There are 5 detection points distributed around and in the center of the workpiece. The maximum value is taken as the oxide layer thickness. The measured oxide layer thickness is 0.009 mm.

[0079] Step 12 Determine the anode breaking laser parameters:

[0080] S121 Focusing: Take an aluminum alloy sample 12 and place it on the processing platform 11, set the scanning speed to 10 mm / s, draw a group of line segments for continuous scanning, and adjust the lifting mechanism 24 to move the laser processing assembly 20 to the back focus coordinate Z1.

[0081] S122 Set frequency: Refer to the waveform diagram of the fiber laser and set the frequency F (60KHz) corresponding to the highest power.

[0082] S123 sets the pulse width: refer to the fiber laser parameter table and set the pulse width PW (100ns) corresponding to the frequency.

[0083] S124 marking line: set the scanning speed to 500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% in sequence, there are 20 marking lines. S125 detection: use a confocal microscope to measure the line width and depth of each marking line in turn.

[0084] S126 determines the line width and power: (The line width gradually increases from shallow to deep as the laser power increases. When the laser power exceeds a certain value, the line width no longer changes with the increase in power.) First, screen out the lines whose line width no longer changes and have no heat-affected zone, and then screen out the lines whose line depth just exceeds the thickness of the oxide layer. The line width and power corresponding to the line are the optimal line width D1 and power W1, where D1 is 0.04mm and W1 is 25%.

[0085] Step 13 Determine the scanning parameters

[0086] S131 Determine the filling spacing: Determine the filling spacing to be D1 / 2, i.e. 0.02mm. (When the filling spacing is equal to the line width, it is the window parameter. At this time, the bottom residue is a sharp triangle, and when the filling spacing gradually decreases, the bottom residue also decreases.)

[0087] S132 Determine the scanning speed: Assume that the spot diameter is D1 (0.04 mm), the laser frequency is F (60 kHz), and the scanning speed is V (500 mm / s), and calculate that the overlap ratio is 80% at this time. (Overlap ratio R = 1-V / D1 F, calculate and determine the scanning speed V).

[0088] S133 determines the light-on / off delay: the light-on / off delay setting value is 50ms.

[0089] S134 Determine the fill pattern: Select parallel line fill. (The fill pattern includes grid, parallel lines, circular lines, etc.)

[0090] S135 determines the filling direction: selects the filling direction of 0 degrees, and the bow-shaped filling. (The filling direction has 0-90 degrees, sequential filling and bow-shaped filling)

[0091] S136 Sample production: Set parameters according to S131-S136 and produce several 25*25mm samples for the next Step 14 test.

[0092] Step 14 Second Scan

[0093] S141 determines the secondary scanning line width and power: the other parameters mentioned above remain unchanged, and the filling distance is set to be equal to D1 / 2 (i.e. 0.02mm), D1 / 2+0.005mm (i.e. 0.025mm), D1 / 2-0.005mm (i.e. 0.015mm), D1 / 2+0.01mm (i.e. 0.03mm), D1 / 2-0.01mm (i.e. 0.01mm), D1 / 2+0.015mm (i.e. 0.035mm), D1 / 2-0.015mm (i.e. 0.005 mm), laser power is equal to W1 / 2, W1 / 2+5%, W1 / 2-5%, W1 / 2+10%, W1 / 2-10%, filling direction is 90 degrees, bow-shaped filling, take a sample of S136, make a 5*5mm small sample on the sample, use a microscope to detect the roughness of the small sample, select the small sample with the lowest roughness, the corresponding filling distance is the secondary scanning line width D2, the corresponding laser power is the secondary scanning power W2; D2 is D1 / 2+0.005mm, that is, 0.025mm; W2 is W1 / 2.

[0094] S142 Sample preparation: According to the secondary scanning line width D2 and secondary scanning power W2 parameters determined in S141, perform secondary scanning on the remaining samples obtained in S136 to prepare for the next step Step 2 test.

[0095] Step 2: Flattening of the aluminum body. The process is as follows: Figure 5 As shown:

[0096] S21 Focus

[0097] S211 back focus focusing: Take a piece of S142 sample and place it on the processing platform 11, set the scanning speed to 10mm / s, draw a group of line segments for continuous scanning, adjust the lifting mechanism 24 to make the laser processing component 20 descend continuously, and record the coordinate point with the strongest flash of the sample as the back focus coordinate Z1.

[0098] S212 Front focus: adjust the lifting mechanism 24 to make the laser processing assembly 20 continue to descend, the sample flash weakens, and continues to descend to the second coordinate point with the strongest flash, which is the front focus coordinate Z2.

[0099] S213 Homogenizing surface focusing: adjust the coordinates of the laser processing component 20 to the middle position between Z1 and Z2, which is the homogenizing surface.

[0100] S22 marking line: Set the pulse width of the fiber laser to 1ns and the continuous laser mode; set the scanning speed to 500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% in sequence, and mark 20 lines.

[0101] S23 detection: Use a confocal microscope to measure the line width and depth of each scribed line in turn.

[0102] S24 Preliminary line width and power: Select the lines that are completely melted, the width no longer increases, and there is no heat-affected zone, and then select the lines with smooth surfaces and no cracks. The line width and power corresponding to the lines are the preliminary line width D and power W, D is 0.04mm, and W is 40%.

[0103] S25 makes small samples: sets the scanning speed to 500mm / s, the filling spacings to D / 2 (i.e. 0.02mm), D / 2+0.005mm (i.e. 0.025mm), D / 2-0.005mm (i.e. 0.015mm), D / 2+0.01mm (i.e. 0.03mm), D / 2-0.01mm (i.e. 0.01mm), D / 2+0.015mm (i.e. 0.035mm), D / 2-0.015mm (i.e. 0.005mm), the powers to W, W+5%, W-5%, W+10%, W-10% respectively, the filling mode to grid, and makes 5*5mm small samples on several samples obtained in S142.

[0104] S26 Confirmation

[0105] S261 short circuit test: using a multimeter The test sample is qualified if it makes a "beeping" sound.

[0106] S262 Observation: Observe and use a confocal microscope to detect the samples, and select the sample with the lowest roughness. The corresponding filling spacing and power parameters are the optimal parameters D3 and W3; D3 is D / 2+0.005mm (i.e. 0.025mm), and W3 is W+5%.

[0107] S27 Sample preparation: According to the optimal parameters D3 and W3 confirmed in S262, a 25*25mm aluminum flattened sample is prepared on the remaining samples obtained in S142 in preparation for the next Step 3 test.

[0108] Step 3 laser highlight polishing, the process is as follows Figure 6 As shown:

[0109] S31 Focusing: Take a piece of S27 sample and place it on the processing platform 11, adjust the lifting mechanism to move the laser processing assembly to the back focus coordinate Z1.

[0110] S32 first polishing: set the pulse width to PW (1ns), the scanning speed to 500mm / s, the filling spacing to D1 / 2 (i.e. 0.02mm), the filling mode to bow, and the filling direction to 0 degree; set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% in sequence, and make 20 5*5 polishing samples.

[0111] S33 detection

[0112] S331 Observation: Observe and examine the samples using a confocal microscope, and select several samples with relatively low roughness.

[0113] S332 gloss measurement: Use a gloss meter to measure the samples selected above. The power corresponding to the sample with the largest GU value is the best first-cast power W4, and W4 is 40% of the set power.

[0114] S34: Preparation of medium sample: take more pieces of S27 sample, set the power to W4, and make 25*25mm medium sample on S27 sample;

[0115] S35 second polishing: Set the scanning speed to 500mm / s, the filling distances are D1 / 2, D1 / 2±0.005mm, D1 / 2±0.01mm, D1 / 2±0.015mm, the filling mode is bow, the filling direction is 90 degrees, the power is 2*W4, 2*W4+5%, 2*W4-5%, 2*W4+10%, 2*W4-10%, and make 5*5mm polishing samples in turn.

[0116] S36 Confirm parameters

[0117] S361 Observation: Observe and examine the polished samples using a confocal microscope, and select several samples with relatively low roughness.

[0118] S362 gloss measurement: Use a gloss meter to measure the samples selected above. The filling distance and power corresponding to the sample with the largest GU value are the optimal filling distance parameter D5 and the optimal power parameter W5. D5 is D1 / 2+0.005, i.e. 0.025mm, and W5 is 70%.

[0119] S363 short circuit test: using a multimeter The resistance of the sample is infinite and it is qualified if there is no "beeping" sound.

[0120] S37 sample production: According to the above S11-S36 process, 10 regular samples are produced, the parameters are checked for reproducibility, and the samples are archived. After testing, the polished surface roughness of the above alloy material samples can reach less than 0.4um, and the surface finish can reach more than 400GU.

[0121] The polishing effects of the laser polishing device in this embodiment under different debugging parameters are as follows: Figure 7 As shown, area A is a polished sample finally made by the debugging method of this embodiment, and its surface roughness is 0.3um and the surface finish is 450GU.

[0122] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A laser polishing device, characterized in that: It includes a fiber laser, a lifting mechanism, a laser processing component and a processing platform; the laser processing component includes a laser light head, a beam expander, a DOE and a galvanometer component; the fiber laser can modulate two modes, pulse laser and continuous laser, and the laser light head outputs Gaussian laser; the Gaussian laser is expanded, shaped, scanned and focused by the beam expander, DOE and galvanometer component in turn and then irradiated onto the processing platform; the laser processing component is arranged on the lifting mechanism, and the lifting mechanism is used to adjust the up and down movement of the laser processing component; the processing platform is located below the galvanometer component.

2. The laser polishing device according to claim 1, characterized in that: The fiber laser is a fiber infrared MOPA single-mode laser.

3. The laser polishing device according to claim 1, characterized in that: The fiber laser is a 50-500W fiber laser.

4. The laser polishing device according to claim 1, characterized in that: The focal length of the galvanometer is 100-260 mm.

5. The laser polishing device according to claim 1, characterized in that: It also includes a base; the lifting mechanism and the processing platform are arranged on the base.

6. The debugging method for performing highlight polishing of aluminum alloy by the laser polishing device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Remove the anodized layer Step 11: Detect the thickness of the oxide layer; Step 12 Determine the anode breaking laser parameters S121 Focusing: placing the aluminum alloy sample on the processing platform, and adjusting the lifting mechanism to move the laser processing assembly to the front focus coordinate or the back focus coordinate; S122 frequency setting: refer to the laser waveform diagram and set the frequency F corresponding to the highest power; S123 sets the pulse width: refer to the laser parameter table to set the pulse width PW corresponding to the frequency F; S124 engraved lines: Set the scanning speed to any value between 100-500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% in sequence, with 20 engraved lines; S125 detection: measure the line width and depth of each engraved line in turn; S126 determines the line width and power: first, select the lines whose line width does not change and have no heat-affected zone, and then select the lines whose line depth just exceeds the thickness of the oxide layer. The line width and power corresponding to the lines are the optimal line width D1 and power W1; Step 13 Determine the scanning parameters S131 Determine the filling spacing: Determine the filling spacing to be D1 / 2; S132 determines the scanning speed: assuming that the spot diameter is D1, the laser frequency is F, the scanning speed is V, and the overlap ratio is R; the overlap ratio R = 1-V / D1*F, R ≥ 80%, and the scanning speed V = (1-R)*D1*F is determined by calculation; S133 determines the switch light delay: the switch light delay setting value is 0-100ms; S134 Determine the filling pattern: select parallel line filling; S135 determines the filling direction: selects 0 degrees, and fills in a bow shape; S136 Sample production: According to the parameters set in S131-S136, several 25*25mm samples are produced for the next step, Step 14 test; Step 14 Second Scan S141 determines the secondary scanning line width and power: the other parameters mentioned above remain unchanged, and the filling distance is set to be equal to D1 / 2, D1 / 2±0.005mm, D1 / 2±0.01mm, D1 / 2±0.015mm, respectively, and the laser power is set to be equal to W1 / 2, W1 / 2±5%, W1 / 2±10%, and the filling direction is 90 degrees, and the filling is in a bow shape. Take a piece of the sample of S136 and make a 5*5mm small sample on the sample; use a microscope to detect the roughness of the small sample, and determine that the filling distance corresponding to the small sample with the lowest roughness is the secondary scanning line width D2, and the corresponding laser power is the secondary scanning power W2; S142 Sample preparation: According to the secondary scanning line width D2 and secondary scanning power W2 parameters determined in S141, perform secondary scanning on the remaining samples obtained in S136 to prepare 25*25mm samples for the next step Step 2 test; Step 2 Flattening of the aluminum body S21 Focusing: Adjust the lifting mechanism to move the laser processing assembly to the middle position between the front focus coordinate and the back focus coordinate; S22 marking line: Set the pulse width of the fiber laser to 1ns, continuous laser mode; set the scanning speed to any value between 100-500mm / s, and then set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 20 marking lines; S23 detection: measure the line width and depth of each engraved line in turn; S24 Preliminary determination of line width and power: Select the lines that are completely melted, the width does not increase, and there is no heat-affected zone, and then select the lines with smooth surfaces and no explosion points. The line width and power corresponding to the lines are the preliminary line width D and power W; S25: Make small samples: keep the scanning speed set in step S22 unchanged, set the filling spacing to D / 2, D / 2±0.005mm, D / 2±0.01mm, D / 2±0.015mm, the power to W, W±5% and W±10%, the filling mode to grid, and make 5*5mm small samples on the samples obtained in S142; S26 Confirm parameters: Use a confocal microscope to detect the samples, and select the sample with the lowest roughness. The corresponding filling spacing and power parameters are the optimal parameters D3 and W3; S27 Sample preparation: According to the optimal parameters D3 and W3 confirmed in S26, a 25*25mm aluminum flattened sample is prepared on the remaining samples obtained in S142 for the next step, Step 3 test; Step 3 Laser highlight polishing S31 Focusing: Take a piece of S27 sample and place it on the processing platform, adjust the lifting mechanism to move the laser processing component to the front focus coordinate or the back focus coordinate; S32 one polishing: set the pulse width to PW, set the scanning speed to any value between 100-500mm / s, the filling spacing to D1 / 2, the filling mode to bow, and the filling direction to 0 degrees; set the power to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or until the scanning burst point, and make 5*5 polishing samples ≤20 in sequence; S33 detection S331 Observation: Observe and examine the samples using a confocal microscope, and select several samples with relatively low roughness; S332 gloss measurement: Use a gloss meter to measure the selected samples. The power corresponding to the sample with the largest GU value is the best first-throw power W4; S34: Preparation of medium sample: take more pieces of S27 sample, set the power to W4, and make 25*25mm medium sample on S27 sample; S35 Second polishing: Set the scanning speed to be the same as step S32, the filling distances are D1 / 2, D1 / 2±0.005mm, D1 / 2±0.01mm, D1 / 2±0.015mm respectively, the filling mode is bow, the filling direction is 90 degrees, the power is 2*W4, 2*W4±5%, 2*W4±10% respectively, and make 5*5mm polishing samples on the medium sample in sequence; S36 Confirm parameters S361 Observation: Observe and examine the polished samples using a confocal microscope, and select several samples with relatively low roughness; S362 gloss measurement: Use a gloss meter to measure the selected samples. The filling distance and power corresponding to the sample with the largest GU value are the optimal filling distance parameter D5 and the optimal power parameter W5; S37 Sample production: Produce multiple regular samples according to the above S11-S36 process, check the reproducibility of the parameters, and archive the samples.

7. The debugging method according to claim 6, characterized in that: The Step 11 of detecting the oxide layer thickness is specifically as follows: using an eddy current film thickness tester to detect the oxide layer thickness, with at least five detection points distributed around the periphery and center of the workpiece, and taking the maximum detection thickness as the oxide layer thickness.

8. The debugging method according to claim 6, characterized in that: In the Step 11, the lifting mechanism is adjusted to move the laser processing component to the front focus coordinate or the back focus coordinate. Specifically, the scanning speed of the fiber laser is set to any value between 1-10 mm / s, and the laser is emitted for continuous scanning. At the same time, the lifting mechanism is adjusted to drive the laser processing component to continuously descend from the highest position, and the coordinate point of the laser processing component when the laser flashes most intensely on the sample for the first time is recorded as the back focus coordinate, and the coordinate point of the laser processing component when the laser flashes most intensely on the sample for the second time is recorded as the front focus coordinate.

9. The debugging method according to claim 6, characterized in that: In the above S26, before using the confocal microscope to detect the sample, it also includes using a multimeter The test sample is qualified if it makes a "beeping" sound during short circuit test.

10. The debugging method according to claim 6, characterized in that: After S362, S363 is also included to measure short circuit: use a multimeter The resistance of the sample is infinite and it is qualified if there is no "beeping" sound.

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