Laser marking system and method for metal surface dazzling and coloring

Abstract

The invention provides a laser marking system and method for metal surface dazzling and coloring, and relates to the technical field of metal surface laser precision machining.The system integrates a femtosecond laser, a nanosecond laser, an optical bread board, a lifting platform, an electric rotating slide, a scanning galvanometer, a focusing lens, a computer control system and an adsorption platform; two laser marking processes of colorful marking and coloring marking are innovatively combined; the femtosecond laser device achieves a colorful effect on the metal surface through ultrashort pulses, and the nanosecond laser device generates a colorful effect of various colors through the heat effect. Automatic switching of the two lasers is controlled through the lifting platform, the computer automatically recognizes the drawing and document process type, and multi-color-zone pattern marking is efficiently completed. The system is simple in structure and convenient to operate, can meet the high-precision double-process marking requirement of the metal surface, and is widely applied to the fields of consumer electronics, anti-counterfeiting technologies and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of metal surface laser precision processing, and in particular to a laser marking system and method for dazzling and coloring metal surfaces. Background Art

[0002] With the widespread application of metal products in consumer electronics, automotive decoration, and personalized customization, the market has placed higher demands on metal surface marking technologies that offer high precision, multiple colors, and customizable patterns. Traditional ink printing, electroplating, and anodizing methods, due to issues such as heavy pollution, unstable colors, and low pattern accuracy, are gradually being replaced by laser color marking technology.

[0003] Existing color marking methods fall into two main categories: one is ultrafast femtosecond laser-based colorful structural color technology, which uses femtosecond lasers to induce micro-nano periodic structures on metal surfaces. This creates a colorful effect under natural light thanks to the grating interference effect. The other is nanosecond laser-based color marking technology, which controls parameters such as defocus, power, and frequency to induce a slight melting or oxidation reaction on the metal surface to create color.

[0004] However, most current laser marking equipment is based on a single laser source, making it difficult to accommodate mixed processing of multiple color styles. Dual laser systems often need to be deployed independently, resulting in large equipment size, high cost, and complex switching. There is a lack of an integrated marking system with a unified optical path structure, flexible control of processing modes, and adaptability to multiple color requirements within large graphic areas. In actual applications, if continuous integrated processing of a colorful pattern area and a colored pattern area is required on the same metal surface, it is often necessary to switch the optical path between two independent systems, move the workpiece, or manually set up two work processes, resulting in large equipment size, cumbersome operation, and process interruption. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser marking system and method for dazzling and colorful metal surfaces, so as to solve the problems in the prior art such as complex laser source switching, bulky equipment, cumbersome operation, and inability to efficiently handle the continuous processing requirements of multi-color areas and multiple patterns.

[0006] To achieve the above objectives, the present invention proposes a laser marking system for dazzling and coloring metal surfaces, comprising a femtosecond laser, a nanosecond laser, an optical breadboard, a lifting platform, an electric rotating glass slide, a scanning galvanometer, a focusing lens, a computer control system, and an adsorption platform; the lifting platform is located at the bottom of the system, the nanosecond laser is located above the lifting platform, the optical breadboard is located between the femtosecond laser and the nanosecond laser, the femtosecond laser is located above the optical breadboard, the electric rotating glass slide is located above the optical breadboard and on one side of the femtosecond laser, a spatial optical path is formed by sequentially connecting a beam expander, a reflector I, and a reflector II, reflector I is located on one side of the beam expander, reflector II is located directly below reflector I, a scanning galvanometer is located on one side of reflector II, and below the scanning galvanometer are sequentially the focusing lens, the marking sample, and the adsorption platform; Preferably, the dazzling process and the beating process of the dual-process system share a workstation, and the adsorption platform is used to fix the same metal sample, so that the processing of the dazzling area and the beating area can be completed in sequence without the need for secondary clamping of the sample; wherein: the adsorption platform is used to fix the metal sample to be processed in the processing area, and the adsorption platform secures the sample thereon through adsorption force to prevent the sample from moving due to vibration or other factors during the processing, thereby ensuring the processing precision and pattern accuracy.

[0007] Preferably, the upper layer of the optical breadboard supports a femtosecond laser and an electrically rotating glass slide, and the lower layer supports a nanosecond laser; the optical breadboard is used to support and integrate optical components to ensure precise transmission of the laser beam; wherein: the femtosecond laser is mainly used to generate micro-nano periodic structures to form a colorful effect on the metal surface; the electrically rotating glass slide can adjust the polarization direction of the laser beam to ensure precise control of the structural color effect; the nanosecond laser is used for thermal effect coloring.

[0008] Preferably, the lifting platform adjusts the position of the nanosecond laser through a computer control system and automatically switches the optical path. The optical path switching time is less than or equal to 5 seconds. The computer control system realizes the processing path planning of the colorful process and the color-marking process through a preset algorithm; wherein: the computer control system manages the start and stop of the femtosecond laser and the nanosecond laser, the lifting platform adjusts and switches the optical path, the processing of the processing drawings and the information transmission of the marking path. The automated control ensures the efficient operation of the system.

[0009] The present invention also provides a laser marking method for dazzling and coloring a metal surface, the steps of which are as follows: Step S1, pretreatment: cleaning the metal surface, including chemical cleaning, ultrasonic cleaning or physical grinding; then, mirror finishing the metal surface, including grinding and polishing. The specific steps are as follows: By removing surface oil, impurities and oxide layers, the metal surface is ensured to be flat and pollution-free, ensuring that the metal surface reaches good processing conditions to ensure the effect and accuracy during the laser marking process; the metal surface is mirror-finished to remove surface roughness, ensure the metal surface is smooth, and create suitable conditions for subsequent laser marking, thereby improving the accuracy and stability of the marking; Step S2, fixing step: fixing the pre-treated metal sample to the adsorption platform, ensuring the stability of the sample position during processing through adsorption force, and avoiding inaccurate marking due to sample displacement; Step S3, parameter setting step: importing the processing drawing file through the computer control system, setting the process parameters of the femtosecond laser and nanosecond laser, including: laser power, scanning speed, filling density and filling method; Step S4, colorful processing step: When the computer control system recognizes the colorful processing area, the femtosecond laser and the electric rotating glass slide are activated. The electric rotating glass slide adjusts the laser polarization state according to the filling angle of the image file, and generates a micro-nano periodic structure on the metal surface by the femtosecond laser, and uses the light interference effect to form a colorful effect; Step S5, coloring processing step: When the coloring area is identified, the computer control system controls the lifting platform to adjust the optical path access of the nanosecond laser, and the thermal effect of the nanosecond laser causes the metal surface to partially melt or oxidize to achieve color marking.

[0010] Preferably, in step S4 and step S5, the computer control system automatically identifies the dazzling color processing area and the color-stamping processing area according to the input processing drawings, and raises and lowers the lifting platform to adjust the height position of the nanosecond laser.

[0011] Therefore, the present invention proposes a laser marking system and method for dazzling and coloring metal surfaces, which has the following beneficial effects: (1) The present invention solves the problems of complex laser source switching, bulky equipment, and cumbersome operation in the prior art by integrating femtosecond laser and nanosecond laser into the same optical path system and automatically switching the laser source through a lifting platform.

[0012] (2) The entire processing process is automatically controlled by a computer control system to ensure the precise coordination of the laser source switching and the processing process, and to achieve high-precision multi-color pattern marking. At the same time, the system can simultaneously meet the needs of high-precision colorful processing and fast large-area coloring through precise automated control, thereby improving the flexibility and accuracy of metal surface marking.

[0013] (3) The shared optical path design of femtosecond laser and nanosecond laser reduces the equipment size and cost, improves the optical path stability, and enhances the overall reliability of the system; the automatic adjustment of the lifting platform enables the laser source to be quickly switched according to demand, avoiding manual intervention, improving processing efficiency, and reducing manual operation.

[0014] (4) Compared with the existing technology, this system has a simple structure and is easy to operate. It can improve production efficiency and reduce costs. At the same time, it can meet the needs of multi-color and multi-pattern marking and is suitable for a wide range of metal product processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of a laser marking system for dazzling and coloring metal surfaces; Figure 2 A flow chart of a laser marking method for dazzling and coloring a metal surface; Figure 3 This is an example diagram of a processing drawing according to an embodiment of the present invention.

[0016] Reference numerals 1. Lifting platform; 2. Nanosecond laser; 3. Optical breadboard; 4. Femtosecond laser; 5. Electric rotating glass slide; 6. Beam expander; 7. Reflector I; 8. Reflector II; 9. Computer control system; 10. Scanning galvanometer; 11. Focusing lens; 12. Marking sample; 13. Adsorption platform. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0018] Unless otherwise defined, technical or scientific terms used in the present invention shall have the ordinary meaning understood by persons of ordinary skill in the art to which the present invention pertains. Terms such as "connect" or "connected" used in the present invention are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0019] Example 1 like Figure 1 As shown, the present invention provides a laser marking system for dazzling and coloring metal surfaces. The system adopts a compact modular design and has a reasonable overall structure, and can provide efficient laser marking capabilities, including: a lifting platform 1, a nanosecond laser 2, an optical breadboard 3, a femtosecond laser 4, an electric rotating glass slide 5, a beam expander 6, a reflector I 7, a reflector II 8, a computer control system 9, a scanning galvanometer 10, a focusing lens 11, a marking sample 12 and an adsorption platform 13.

[0020] The lifting platform 1 is located at the bottom of the system, supporting and adjusting the height positions of the nanosecond laser 2 and the femtosecond laser 4, ensuring that the femtosecond laser 4 and the nanosecond laser 2 can automatically switch in the same optical path system; the nanosecond laser 2 is located above the lifting platform, and the laser generated by the nanosecond laser 2 produces a thermal effect on the metal surface, causing local melting or oxidation of the surface material, thereby forming different color effects; the power, frequency and other parameters of the laser can be adjusted through the computer control system 9, and the nanosecond laser 2 can control the size of the thermal effect, thereby generating rich color changes on the metal surface, which is widely used in fast coloring of larger areas.

[0021] The optical breadboard 3 is located between the femtosecond laser 4 and the nanosecond laser 2, providing support and fixation for them; the femtosecond laser 4 is located above the optical breadboard 3 and is mainly used to form micro-nano periodic structures on the metal surface; through extremely short laser pulses, the femtosecond laser 4 can excite local nonlinear effects on the metal surface, generating micro-nano-level structures. These microstructures exhibit stable and adjustable structural colors through the interference or diffraction effects of light, which appear to be colorful to the human eye.

[0022] The electrically rotating glass slide 5 is located above the optical breadboard 3 and is connected to the femtosecond laser 4, which is used to change the polarization state of the laser. During the colorful processing by the femtosecond laser 4, the micro-nanostructure of the metal surface depends on the polarization direction of the laser. Therefore, the electrically rotating glass slide 5 can accurately adjust the polarization angle of the laser beam to optimize the stability and adjustability of the structural color.

[0023] The spatial optical route is formed by connecting the beam expander 6, the reflector I7 and the reflector II8 in sequence. The reflector I7 is located to the right of the beam expander 6, and the reflector II8 is located directly below the reflector I7. After the laser beams of the reflectors I7 and II8 pass through the beam expander 6, the beam spot becomes larger and the divergence angle becomes smaller, which is conducive to the focusing lens 11 focusing the laser beam to a smaller point. The three together adjust the scanning path and focus of the laser beam to ensure the accuracy and consistency of the marking.

[0024] The scanning galvanometer 10 is located directly to the right of the reflector II 8 and is responsible for quickly scanning the laser beam to the sample surface to accurately complete the marking task; below the scanning galvanometer 10 are the focusing lens 11, the marking sample 12 and the adsorption platform 13 in sequence; the focusing lens 11 ensures that the laser beam is focused on the sample surface to ensure the fineness of the mark; the marking sample 12 is placed on the adsorption platform 13, and the adsorption platform 13 secures the sample on it through adsorption force to prevent the sample from moving due to vibration or other factors during the processing, thereby ensuring the processing precision and pattern accuracy.

[0025] The computer control system 9 is the core control unit of the entire system, responsible for managing the start and stop of the femtosecond laser 4 and the nanosecond laser 2, the adjustment of the lifting platform 1, the rotation of the electric rotating glass slide 5, and the control of the scanning galvanometer 10; the computer control system 9 ensures the coordinated work of the femtosecond laser 4 and the nanosecond laser 2 during the processing through precise automated control, and automatically identifies the colorful processing area and the color-stamping processing area according to the input processing drawings, ensuring the smooth progress and efficient operation of the processing process.

[0026] Example 2 like Figure 2 As shown, the present invention also provides a laser marking method for dazzling and coloring a metal surface, comprising the following steps: S1. Pretreatment: Clean the metal surface, including chemical cleaning, ultrasonic cleaning or physical polishing. Then, perform mirror treatment on the metal surface, including grinding and polishing. The specific steps are as follows: S11. Clean and pre-treat the metal surface by removing surface oil, impurities and oxide layer to ensure that the metal surface is flat and pollution-free to ensure the effect and accuracy of the laser marking process. This pre-treatment step includes chemical cleaning, ultrasonic cleaning or physical polishing to ensure that the metal surface reaches good processing conditions.

[0027] S12. Mirror the metal surface by grinding, polishing, etc. to remove surface roughness to ensure a smooth metal surface and create suitable conditions for subsequent laser marking to improve the accuracy and stability of the marking. The metal surface needs to be in a mirror state so that the colorful processing effect is better.

[0028] S2. Fixation: Fix the pre-treated metal sample to the adsorption platform and ensure the stability of the sample position during processing through adsorption force. Specifically: After cleaning and mirror finishing, the metal sample is fixed to the adsorption platform. The adsorption platform is a key component to ensure the stable position of the metal sample during laser processing. Through adsorption force, the sample is firmly fixed in the processing area, avoiding position displacement of the sample due to vibration or external force during processing.

[0029] S3. Parameter Setting: The processing diagram is imported into the computer control system, and the process parameters of the femtosecond laser and nanosecond laser are set, including laser power, scanning speed, fill density, and fill method. After the processing diagram is set, the computer automatically identifies the color processing area and the color processing area.

[0030] S4. Colorful Processing: When the computer control system identifies the colorful processing area, the femtosecond laser and the motorized rotating glass slide are activated. The motorized rotating glass slide adjusts the laser polarization state according to the fill angle of the pattern. The femtosecond laser generates micro-nano periodic structures on the metal surface, and the optical interference effect creates a colorful effect. During this process, the rotation angle of the motorized rotating glass slide changes with the fill angle of the pattern, ensuring that the laser polarization direction always remains parallel to the fill direction.

[0031] S5. Color marking: When the color marking area is identified, the computer control system controls the lifting platform to adjust the optical path of the nanosecond laser. The thermal effect of the nanosecond laser causes the metal surface to partially melt or oxidize, achieving color marking. The specific steps are as follows: S51. The computer control system controls the automatic adjustment of the lifting platform to introduce the nanosecond laser beam into the same optical path, and performs nanosecond color processing after the optical path is switched; S52, uses MOPA laser to emit light, and cooperates with scanning galvanometer to achieve color effect on the surface of metal materials; Nanosecond lasers have relatively long pulse widths and more concentrated energy, which can produce specific color changes on the surface of metal materials to meet processing requirements such as decoration or identification. The entire processing process is automatically controlled by a computer control system to ensure the switching of the laser source and the precise coordination of the processing process, ultimately achieving high-precision multi-color pattern marking.

[0032] The present invention will be further described below through specific implementation cases.

[0033] like Figure 3 As shown, the processing drawings are divided into a colorful area and a colored area. The colorful area is represented by a pure black legend; the colored area is divided into three process parameters, parameter one is represented by a dotted line legend, parameter two is represented by a large chessboard legend, and parameter three is represented by a small chessboard legend; among them, the femtosecond laser and nanosecond laser used in this embodiment are both infrared band light sources, the femtosecond laser power is 30W, and the pulse width is less than 500fs. The nanosecond laser uses an infrared MOPA laser with a power of 30W, and the laser frequency and pulse width are adjustable.

[0034] When processing the colorful area, the power of the femtosecond laser was set to 25%, the scanning speed of the galvanometer was 1000 mm / s, the frequency was 200 kHz, the filling method was bow filling, the filling density was 0.03 mm, and the filling angle was 0 degrees.

[0035] When processing the colored area, the power of the MOPA laser is set to 25% and the galvanometer scanning speed is 1000 mm / s.

[0036] Among them: the process parameters of the coloring parameter one are: frequency is 300KHz, filling method is fast filling, filling density is 0.002mm, filling angle is 90 degrees, and pulse width is 4ns; the process parameters of the coloring parameter two are: frequency is 700KHz, filling method is fast filling, filling density is 0.002mm, filling angle is 90 degrees, and pulse width is 8ns; the process parameters of the coloring parameter three are: frequency is 700KHz, filling method is fast filling, filling density is 0.001mm, filling angle is 90 degrees, and pulse width is 8ns.

[0037] The coloring color corresponding to coloring parameter one is blue, the coloring color corresponding to coloring parameter two is black, and the coloring color corresponding to coloring parameter three is brown. The metal material in this example is stainless steel. First, the metal surface is cleaned and pretreated; then, the metal surface is mirror-finished, and the obtained mirror stainless steel metal material is fixed to the adsorption platform and then the system is started to complete subsequent processing work.

[0038] It is worth noting that the contents not elaborated in detail in the present invention are all prior art and are well known to those skilled in the art.

[0039] Therefore, the present invention provides a laser marking system and method for dazzling and colorful metal surfaces. Through technical integration and automated control, it solves the problems of complex optical path switching of dual laser systems, bulky equipment, low processing efficiency of multi-color areas, poor process compatibility, and unstable polarization state control in traditional technologies, realizes continuous high-precision processing of multi-color areas, and meets the needs of consumer electronics, anti-counterfeiting technology and other fields for multi-color and high-flexibility marking of metal surfaces.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A laser marking system for dazzling and coloring metal surfaces, comprising a femtosecond laser, a nanosecond laser, an optical breadboard, a lifting platform, an electric rotating glass slide, a scanning galvanometer, a focusing lens, a computer control system, and an adsorption platform, characterized by: The lifting platform is located at the bottom of the system, the nanosecond laser is located above the lifting platform, the optical breadboard is located between the femtosecond laser and the nanosecond laser, the femtosecond laser is located above the optical breadboard, the electric rotating glass slide is located above the optical breadboard and on the side of the femtosecond laser, the spatial optical route is formed by the beam expander and the reflector I and reflector II connected in sequence, reflector I is located on the side of the beam expander, reflector II is located directly below reflector I, the scanning galvanometer is located on the side of reflector II, and below the scanning galvanometer are the focusing lens, marking sample and adsorption platform in sequence.

2. The laser marking system for dazzling and coloring metal surfaces according to claim 1, characterized in that: The dazzling process and the striking process of the dual-process system share a working station. The adsorption platform is used to fix the same metal sample, so that the dazzling area and the striking area can be processed in sequence without secondary clamping of the sample.

3. The laser marking system for dazzling and coloring metal surfaces according to claim 1, characterized in that: The upper layer of the optical breadboard supports a femtosecond laser and an electrically rotating glass slide, and the lower layer supports a nanosecond laser.

4. The laser marking system for dazzling and coloring metal surfaces according to claim 1, characterized in that: The lifting platform adjusts the position of the nanosecond laser through a computer control system and automatically switches the optical path, and the optical path switching time is less than or equal to 5 seconds; the computer control system realizes the processing path planning of the colorful process and the color-beating process through a preset algorithm.

5. A laser marking method for dazzling and coloring metal surfaces, characterized in that: The following steps are involved: Step S1, pretreatment: First, the metal surface is cleaned, including chemical cleaning, ultrasonic cleaning or physical grinding; then, the metal surface is mirror-treated, including grinding and polishing; Step S2, fixing: fixing the pretreated metal sample to the adsorption platform by adsorption force; Step S3, parameter setting: importing the processing drawing file through the computer control system, setting the process parameters of the femtosecond laser and nanosecond laser, including: laser power, scanning speed, filling density and filling method; Step S4, Colorful Processing: When the computer control system identifies the colorful processing area, the femtosecond laser and the electric rotating glass slide are activated. The electric rotating glass slide adjusts the laser polarization state according to the filling angle of the image file, and generates micro-nano periodic structures on the metal surface by the femtosecond laser, and uses the light interference effect to form a colorful effect; Step S5, coloring processing: When the coloring area is identified, the computer control system controls the lifting platform to adjust the optical path access of the nanosecond laser, and the thermal effect of the nanosecond laser causes the metal surface to partially melt or oxidize to achieve color marking.

6. The method for laser marking a metal surface with dazzling colors and colors according to claim 5, characterized in that: The computer control system automatically identifies the dazzling color processing area and the color punching processing area according to the input processing drawings, and raises and lowers the lifting platform to adjust the height position of the nanosecond laser.

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