An asynchronous composite polishing method and device for coupling multiple lasers

Abstract

The present invention provides an asynchronous composite polishing method and device for coupling multiple lasers, belonging to the technical field of laser processing. The method includes: detecting the surface roughness of the component to be polished; polishing the component to be polished according to the surface roughness to obtain a polished component; when Sa≥3μm, ultrafast laser is used for polishing, and then, in a protective atmosphere, continuous laser and short-pulse laser are sequentially used for polishing; when 0.5μm≤Sa<3μm, continuous laser and short-pulse laser are sequentially used for polishing; when Sa<0.5μm, short-pulse laser is used for polishing; detecting the surface roughness of the polished component; if the requirement is not met, re-polishing is performed. Compared with the single-laser polishing method, the method provided by the present invention has a wide application range and good polishing effect, can not only obtain a large surface roughness reduction rate, but also obtain a small surface roughness.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, and in particular, to an asynchronous composite polishing method and device for coupling multiple lasers. Background Art

[0002] Laser polishing is a new surface polishing technology, which has the advantages of pollution-free, wide range of processing objects, stable polishing quality and easy automation, and has attracted great attention of researchers. Laser polishing can be applied to various types of materials such as metals, glasses and ceramics, and has good application prospects in the fields of aviation, aerospace, molds, automobiles, electronics and medical devices.

[0003] In the prior art, the laser polishing mechanisms mainly include ablation gasification mechanism, excessive melting mechanism and shallow surface layer melting mechanism, and various laser polishing mechanisms are generally applied separately. However, the ablation gasification mechanism and the excessive melting mechanism are only suitable for polishing surfaces with relatively large original roughness, while the shallow surface layer melting mechanism is suitable for surfaces with relatively small original roughness. At the same time, under the ablation gasification mechanism or the excessive melting mechanism, laser polishing can obtain a relatively large surface roughness reduction rate, but the surface roughness of the polished surface is still relatively large, while under the shallow surface layer melting mechanism, the surface roughness reduction rate of laser polishing is relatively small, but a relatively small surface roughness can be obtained. Therefore, the surface polishing effect obtained by the current laser polishing process is limited, and it is difficult to balance a relatively large surface roughness reduction rate and a relatively small surface roughness. Summary of the Invention

[0004] The problem solved by the present invention is how to provide a laser polishing method that can balance a relatively large surface roughness reduction rate and a relatively small surface roughness.

[0005] To solve at least one aspect of the above problems, the present invention provides an asynchronous composite polishing method for coupling multiple lasers, including the following steps:

[0006] Step S1, detecting the surface roughness of the component to be polished to obtain a first detection result;

[0007] Step S2, polishing the component to be polished according to the first detection result to obtain a polished component; when the surface roughness of the component to be polished is greater than or equal to 3 μm, the surface of the component to be polished is polished by an ultrafast laser, and then, in a protective atmosphere, the component to be polished is polished by a continuous laser and a short-pulse laser in sequence; when the surface roughness of the component to be polished is greater than or equal to 0.5 μm and less than 3 μm, the component to be polished is polished by the continuous laser and the short-pulse laser in sequence in a protective atmosphere; when the surface roughness of the component to be polished is less than 0.5 μm, the component to be polished is polished by the short-pulse laser in a protective atmosphere;

[0008] Step S3: Detect the surface roughness of the polished component to obtain a second detection result;

[0009] Step S4: Judge according to the second detection result and the preset roughness. If the requirement of the preset roughness is not met, laser polish the polished component again.

[0010] Preferably, in step S2, the surface of the component to be polished is polished by an ultrafast laser, including:

[0011] The surface of the component to be polished is polished by an infrared picosecond laser with a pulse width of 8 ps, a laser power of 20 W, a scanning speed of 1000 mm / s, a track overlap rate of 95%, a repetition frequency of 400 kHz, a focused spot diameter of 20 μm, a polishing path of "bow" shape, polished 3 - 5 times, and the component to be polished is rotated 90° after each polishing.

[0012] Preferably, in step S2, the method of polishing by a continuous laser includes:

[0013] The surface of the component to be polished is polished by an infrared continuous laser with a laser power of 200 W, a scanning speed of 500 mm / s, a track overlap rate of 90%, a focused spot diameter of 100 μm, a polishing path of "bow" shape, polished 3 - 5 times, and the component to be polished is rotated 90° after each polishing.

[0014] Preferably, in step S2, the method of polishing by a short - pulse laser includes:

[0015] The surface of the component to be polished is polished by an infrared nanosecond laser with a pulse width of 100 ns, a laser power of 350 W, a scanning speed of 1000 mm / s, a track overlap rate of 90%, a repetition frequency of 10 kHz, a focused spot diameter of 1000 μm, a polishing path of "bow" shape, polished 3 - 5 times, and the component to be polished is rotated 90° after each polishing.

[0016] The present invention detects the surface roughness of the component to be polished, obtains the surface roughness of the component to be polished, and selects different process routes according to its surface roughness. Among them, when the surface roughness is greater than or equal to 3 μm, ultrafast laser is first used to remove the surface layer of the component to be polished by ablation and gasification mechanism to reduce the peak-valley difference on its rough surface as a whole. Then, in a protective atmosphere, continuous laser is used to completely melt the surface layer of the component to be polished by over-melting mechanism, and the melt is smoothed on the surface under the action of Marangoni effect. Then, short-pulse laser is used to melt the surface of the component to be polished to a lower degree by shallow surface layer melting mechanism, and the melt is smoothed on the surface under the action of capillary force to achieve a better polishing effect. Correspondingly, when the surface roughness is greater than or equal to 0.5 μm and less than 3 μm, polishing is carried out by continuous laser and short-pulse laser in turn in a protective atmosphere. When the surface roughness is less than 0.5 μm, only short-pulse laser is needed for polishing in a protective atmosphere. By polishing with the above polishing method, the surface roughness reduction rate of the components to be polished with different initial surface roughnesses can reach more than 90%, and the surface roughness is reduced to less than 80 nm. The asynchronous composite polishing method coupling multiple lasers provided by the present invention is applicable to the polishing of components to be polished with different surface roughnesses in the initial state, and can obtain a large surface roughness reduction rate and a small surface roughness under different surface roughness conditions.

[0017] On the other hand, the present invention also provides an asynchronous composite polishing device coupling multiple lasers for implementing the asynchronous composite polishing method coupling multiple lasers as described above, including a base, a first laser polishing module, a second laser polishing module, a third laser polishing module and a surface roughness detection module. The first laser polishing module, the second laser polishing module, the third laser polishing module and the surface roughness detection module are all located above the base;

[0018] Among them, the first laser polishing module is used to implement ultrafast laser polishing;

[0019] The second laser polishing module is used to implement continuous laser polishing;

[0020] The third laser polishing module is used to implement short-pulse laser polishing;

[0021] The surface roughness detection module is used to detect the surface roughness of the component to be polished.

[0022] Preferably, the asynchronous composite polishing device coupling multiple lasers further includes a cavity, an air inlet valve and an air outlet valve are arranged on the cavity, and the first laser polishing module, the second laser polishing module, the third laser polishing module and the surface roughness detection module are all located in the cavity.

[0023] Preferably, the asynchronous composite polishing device for coupling multiple lasers further includes a gas sensor located inside the cavity for detecting the oxygen concentration inside the cavity.

[0024] Preferably, the asynchronous composite polishing device for coupling multiple lasers further includes a displacement stage disposed on the base, and the displacement stage is used to drive the component to be polished to move below the first laser polishing module, the second laser polishing module, the third laser polishing module, and the surface roughness detection module.

[0025] Preferably, the first laser polishing module includes an infrared picosecond fiber laser, a first collimating and beam expanding mirror, a first scanning galvanometer, and a first focusing field lens. The infrared picosecond laser emitted by the infrared picosecond fiber laser forms a first focused spot after passing through the first collimating and beam expanding mirror, the first scanning galvanometer, and the first focusing field lens in sequence; the second laser polishing module includes an infrared continuous fiber laser, a second collimating and beam expanding mirror, a second scanning galvanometer, and a second focusing field lens. The infrared continuous laser emitted by the infrared continuous fiber laser forms a second focused spot after passing through the second collimating and beam expanding mirror, the second scanning galvanometer, and the second focusing field lens in sequence; the third laser polishing module includes an infrared nanosecond fiber laser, a third collimating and beam expanding mirror, a third scanning galvanometer, and a third focusing field lens. The infrared nanosecond laser emitted by the infrared nanosecond fiber laser forms a third focused spot after passing through the third collimating and beam expanding mirror, the third scanning galvanometer, and the third focusing field lens in sequence.

[0026] Preferably, the surface roughness detection module includes a laser confocal microscope or a roughness measuring instrument.

[0027] The asynchronous composite polishing device for coupling multiple lasers provided by the present invention includes a base, a first laser polishing module, a second laser polishing module, a third laser polishing module, and a surface roughness detection module. It can judge the surface roughness of the component to be polished through the surface roughness detection module, and then according to the detection result of the surface roughness, select to place the component to be polished below the first laser polishing module, the second laser polishing module, or the third laser polishing module for polishing. By combining different laser polishing mechanisms, while obtaining a large surface roughness reduction rate, a small surface roughness can also be obtained. Description of the Drawings

[0028] Figure 1 Schematic diagram of the process of the asynchronous composite polishing method for coupling multiple lasers in the embodiment of the present invention Figure 1 ;

[0029] Figure 2 Schematic diagram of the process of the asynchronous composite polishing method for coupling multiple lasers in the embodiment of the present invention Figure 2 ;

[0030] Figure 3 Schematic diagram of the effect of the asynchronous composite polishing method for coupling multiple lasers in the embodiment of the present invention;

[0031] Figure 4 Schematic structure of the asynchronous composite polishing device for coupling multiple lasers in the embodiment of the present invention Figure 1 ;

[0032] Figure 5 Schematic diagram of the structure of the cavity in the embodiment of the present invention;

[0033] Figure 6 Schematic structure of the asynchronous composite polishing device for coupling multiple lasers in the embodiment of the present invention Figure 2 ;

[0034] Figure 7 Three-dimensional surface topography map of the asynchronous composite polishing of the Stavax-ESR martensitic die steel coupled with multiple lasers in the embodiment of the present invention;

[0035] Figure 8 Macrophotograph of the Stavax-ESR martensitic die steel after asynchronous composite polishing coupled with multiple lasers in the embodiment of the present invention.

[0036] Explanation of reference numerals:

[0037] 1. Base; 2. First laser polishing module; 21. First collimating and beam expanding lens; 22. First scanning galvanometer; 23. First focusing field lens; 3. Second laser polishing module; 31. Second collimating and beam expanding lens; 32. Second scanning galvanometer; 33. Second focusing field lens; 4. Third laser polishing module; 41. Third collimating and beam expanding lens; 42. Third scanning galvanometer; 43. Third focusing field lens; 5. Surface roughness detection module; 6. Cavity; 61. Intake valve; 62. Exhaust valve; 7. Gas sensor; 8. Displacement stage. Detailed implementation manners

[0038] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is provided.

[0039] It should be noted that, without conflict, the features in the embodiments of the present invention can be combined with each other. At the same time, it should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here.

[0040] An asynchronous composite polishing method for coupling multiple lasers provided by an embodiment of the present invention is as follows Figure 1 shown, and includes the following steps:

[0041] Step S1, detecting the surface roughness of the component to be polished to obtain a first detection result;

[0042] Step S2, polishing the component to be polished according to the first detection result to obtain a polished component; when the surface roughness of the component to be polished is greater than or equal to 3 μm, using an ultrafast laser to polish the surface of the component to be polished, and then in a protective atmosphere, successively using a continuous laser and a short-pulse laser to polish the component to be polished; when the surface roughness of the component to be polished is greater than or equal to 0.5 μm and less than 3 μm, successively using the continuous laser and the short-pulse laser to polish the component to be polished in a protective atmosphere; when the surface roughness of the component to be polished is less than 0.5 μm, using the short-pulse laser to polish the component to be polished in a protective atmosphere;

[0043] Step S3, detecting the surface roughness of the polished component to obtain a second detection result;

[0044] Step S4, judging according to the second detection result and a preset roughness. If the requirement of the preset roughness is not met, re-polish the polished component by laser.

[0045] In the embodiment of the present invention, by detecting the surface roughness of the component to be polished, obtaining the surface roughness of the component to be polished, and selecting different process routes according to its surface roughness. Among them, when the surface roughness is greater than or equal to 3 μm, first use an ultrafast laser to remove the surface layer of the component to be polished by ablation and gasification mechanism to overall reduce the peak-valley difference on its rough surface, and then in a protective atmosphere, use a continuous laser to completely melt the surface layer of the component to be polished by an over-melting mechanism, and make the melt smooth the surface under the action of the Marangoni effect. Then, use a short-pulse laser to perform a lower degree of melting on the surface of the component to be polished by a shallow surface layer melting mechanism, and make the melt smooth the surface under the action of capillary force to achieve a better polishing effect; correspondingly, when the surface roughness is greater than or equal to 0.5 μm and less than 3 μm, successively polish by a continuous laser and a short-pulse laser in a protective atmosphere. When the surface roughness is less than 0.5 μm, only need to polish by a short-pulse laser in a protective atmosphere; by polishing with the above polishing method, the surface roughness reduction rate of the component to be polished with different initial surface roughnesses can reach more than 90%, and the surface roughness is reduced to below 80 nm.

[0046] As Figure 2As shown in the figure, before polishing the component to be polished, the surface roughness Sa of its surface is first measured. According to the range of Sa, it is divided into three different situations. When Sa≥3μm, since the surface of the component to be polished is relatively rough, ultrafast laser is first used for polishing. The surface layer of the component to be polished is removed through the ablation and gasification mechanism, and the peak-valley difference on its surface is reduced as a whole, thereby reducing the surface roughness of the component to be polished. Then, under a protective atmosphere, continuous laser is used for polishing. Through the over-melting mechanism, the surface layer of the component to be polished is completely melted, and the melt smooths the surface under the action of the Marangoni effect, further reducing its surface roughness. Furthermore, under a protective atmosphere, short-pulse laser is used for polishing. Through the shallow surface layer melting mechanism, the surface layer of the component to be polished is melted to a weak degree, and the melt further smooths the surface under the action of capillary force, achieving a lower surface roughness while having a high surface roughness reduction rate.

[0047] For the component to be polished with 0.5μm≤Sa<3μm, continuous laser is directly used for polishing, and then short-pulse laser is used for polishing; for the component to be polished with Sa<0.5μm, short-pulse laser is directly used for polishing.

[0048] Selecting different polishing process routes according to the surface roughness of the component to be polished can achieve a large surface roughness reduction rate while also obtaining a small surface roughness. After polishing, the surface roughness can be controlled at the nanoscale. If the component to be polished with Sa≥0.5μm is only polished with ultrafast laser or continuous laser, it is difficult to obtain a small surface roughness. And if the component to be polished with Sa<0.5μm is polished with ultrafast laser first, it will instead lead to an increase in surface roughness and it is difficult to achieve the polishing effect.

[0049] In step S1, a laser confocal microscope or a roughness measuring instrument is used to measure the surface roughness Sa of the component to be polished, which is convenient for determining different polishing process flows according to the detection results of the surface roughness.

[0050] In step S2, according to the detection results of the surface roughness in step S1, different polishing processes are selected to polish the component to be polished. Specifically:

[0051] When the surface roughness of the component to be polished is greater than or equal to 3μm, ultrafast laser is used to polish the surface of the component to be polished, and then under a protective atmosphere, continuous laser and short-pulse laser are successively used to polish the component to be polished;

[0052] When the surface roughness of the component to be polished is greater than or equal to 0.5μm and less than 3μm, continuous laser and short-pulse laser are successively used to polish the component to be polished;

[0053] When the surface roughness of the component to be polished is less than 0.5 μm, a short-pulse laser is used to polish the component to be polished.

[0054] That is to say, according to the mechanisms of different laser polishing processes, the embodiments of the present invention take the coupling of multiple laser polishing mechanisms as the basic idea, set different polishing methods for components to be polished with different surface roughnesses, have a wider application range, and can achieve better polishing effects.

[0055] The asynchronous composite polishing method coupling multiple lasers provided by the embodiments of the present invention is applicable to the surface polishing of components such as metals and ceramics, and can be used as a post-treatment means for laser processing procedures such as additive manufacturing and laser shock peening.

[0056] Exemplarily, using an ultrafast laser to polish the surface of the component to be polished includes:

[0057] Using an infrared picosecond laser to polish the surface of the component to be polished, with a pulse width of 8 ps, a laser power of 20 W, a scanning speed of 1000 mm / s, a track overlap rate of 95%, a repetition frequency of 400 kHz, a focused spot diameter of 20 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

[0058] The method of using a continuous laser for polishing includes:

[0059] Using an infrared continuous laser to polish the surface of the component to be polished, with a laser power of 200 W, a scanning speed of 500 mm / s, a track overlap rate of 90%, a focused spot diameter of 100 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

[0060] The method of using a short-pulse laser for polishing includes:

[0061] Using an infrared nanosecond laser to polish the surface of the component to be polished, with a pulse width of 100 ns, a laser power of 350 W, a scanning speed of 1000 mm / s, a track overlap rate of 90%, a repetition frequency of 10 kHz, a focused spot diameter of 1000 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

[0062] Exemplarily, the protective atmosphere includes a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere, and the protective atmosphere can avoid the deterioration of the surface quality caused by the oxidation of the surface of the component to be polished during the polishing process.

[0063] Among them, the polishing path is in the shape of a "bow", that is, the polishing path is planned in a folding-back form. After reaching the end, translation is performed, and the shape of the path is similar to the character "bow". The overall path of the "bow"-shaped polishing path is shorter and the coverage rate is higher, which can improve the effect of laser polishing.

[0064] In step S3, after polishing the component to be polished to obtain a polished component, the surface roughness of the polished component is detected again.

[0065] In step S4, according to the surface roughness detection result (the second detection result) of the polished component and the preset roughness, if the requirement of the preset roughness is not met, the polished component is re-polished by laser.

[0066] That is to say, the second detection result is compared with the preset roughness. If the second detection result ≤ the preset roughness, the polishing requirement is met and the polishing is completed. If the second detection result > the preset roughness, the polishing requirement is not met, and it is necessary to continue to repeat the polishing process in step S2 until the polishing requirement is met.

[0067] Figure 3 It is a schematic diagram of the asynchronous composite polishing method coupling multiple lasers provided by an embodiment of the present invention. For a component to be polished with a surface roughness greater than or equal to 3 μm, after passing through the ablation gasification mechanism (ultrafast laser polishing), the over-melting mechanism (continuous laser polishing), and the shallow surface layer melting mechanism (short pulse laser polishing) in sequence, by making full use of the characteristics of different mechanisms, the surface roughness can reach the nanometer level, achieving a good laser polishing effect.

[0068] Another embodiment of the present invention provides an asynchronous composite polishing device coupling multiple lasers for implementing the asynchronous composite polishing method coupling multiple lasers as described above, including a base 1, a first laser polishing module 2, a second laser polishing module 3, a third laser polishing module 4, and a surface roughness detection module 5. The first laser polishing module 2, the second laser polishing module 3, the third laser polishing module 4, and the surface roughness detection module 5 are all located above the base;

[0069] Among them, the first laser polishing module 2 is used to implement ultrafast laser polishing;

[0070] The second laser polishing module 3 is used to implement continuous laser polishing;

[0071] The third laser polishing module 4 is used to implement short pulse laser polishing;

[0072] The surface roughness detection module 5 is used to detect the surface roughness of the component to be polished.

[0073] Exemplarily, the surface roughness detection module 5 includes a laser confocal microscope or a roughness measuring instrument.

[0074] As Figure 4 shown, the asynchronous composite polishing device coupling multiple lasers provided by the embodiment of the present invention includes a base 1, a first laser polishing module 2, a second laser polishing module 3, a third laser polishing module 4, and a surface roughness detection module 5. The surface roughness of the component to be polished can be judged through the surface roughness detection module 5, and then according to the detection result of the surface roughness, the component to be polished is selected to be placed under the first laser polishing module 2, the second laser polishing module 3, or the third laser polishing module 4 for polishing. By combining different laser polishing mechanisms, while obtaining a large surface roughness reduction rate, a small surface roughness can also be obtained.

[0075] In one embodiment, as Figure 5 shown, the asynchronous composite polishing device coupling multiple lasers further includes a cavity 6. An air inlet valve 61 and an air outlet valve 62 are arranged on the cavity 6. The first laser polishing module 2, the second laser polishing module 3, the third laser polishing module 4, and the surface roughness detection module 5 are all located in the cavity 6.

[0076] The cavity 6 can store a protective gas. When polishing needs to be carried out in a protective atmosphere, the protective gas can be introduced into the cavity 6 through the air inlet valve 61, and the air in the cavity 6 can be discharged through the air outlet valve 62.

[0077] Exemplarily, the cavity 6 is made of transparent acrylic material, which is convenient for observation and operation during the polishing process. The air inlet valve 61 and the air outlet valve 62 are respectively located on opposite sides of the cavity 6. When the protective gas is introduced through the air inlet valve 61, it is convenient for the air in the cavity 6 to be discharged through the air outlet valve 62.

[0078] In one embodiment, as Figure 4 and 6 shown, the asynchronous composite polishing device coupling multiple lasers further includes a gas sensor 7. The gas sensor 7 is located in the cavity 6 and is used to detect the oxygen concentration in the cavity 6.

[0079] The gas sensor 7 can detect the oxygen concentration in the cavity 6. During the process of introducing the protective gas into the cavity 6, it can be judged through the gas sensor 7 whether the requirements for polishing are met. When the requirements are met, the introduction of the protective gas into the cavity 6 can be stopped.

[0080] In one embodiment, as Figure 4 and 6As shown, the asynchronous composite polishing device for coupling multiple lasers further includes a displacement stage 8. The displacement stage 8 is disposed on the base 1, and the displacement stage 8 is used to drive the component to be polished to move below the first laser polishing module 2, the second laser polishing module 3, the third laser polishing module 4, and the surface roughness detection module 5.

[0081] Place the component to be polished on the displacement stage 8. By adjusting the displacement stage 8, the component to be polished can be respectively located below the first laser polishing module 2, the second laser polishing module 3, the third laser polishing module 4, and the surface roughness detection module 5 to complete different polishing processes.

[0082] Further, the displacement stage 8 can also be a displacement stage 8 capable of multi-dimensional movement, which can be adjusted in the up and down, left and right, and front and back directions. It can not only move the component to be polished below different devices, but also adjust the focusing situation and the polishing area.

[0083] In one embodiment, as Figure 6 shown, the first laser polishing module 2 includes an infrared picosecond fiber laser (not shown in the figure), a first collimating and beam expanding mirror 21, a first scanning galvanometer 22, and a first focusing field lens 23. The infrared picosecond laser emitted by the infrared picosecond fiber laser passes through the first collimating and beam expanding mirror 21, the first scanning galvanometer 22, and the first focusing field lens 23 in sequence to form a first focused spot; the second laser polishing module 3 includes an infrared continuous fiber laser (not shown in the figure), a second collimating and beam expanding mirror 31, a second scanning galvanometer 32, and a second focusing field lens 33. The infrared continuous laser emitted by the infrared continuous fiber laser passes through the second collimating and beam expanding mirror 31, the second scanning galvanometer 32, and the second focusing field lens 33 in sequence to form a second focused spot; the third laser polishing module 4 includes an infrared nanosecond fiber laser (not shown in the figure), a third collimating and beam expanding mirror 41, a third scanning galvanometer 42, and a third focusing field lens 43. The infrared nanosecond laser emitted by the infrared nanosecond fiber laser passes through the third collimating and beam expanding mirror 41, the third scanning galvanometer 42, and the third focusing field lens 43 in sequence to form a third focused spot.

[0084] Exemplarily, the maximum average power of the infrared picosecond fiber laser in the first laser polishing module 2 is 50W. The laser emitted by it passes through the first collimating and beam expanding mirror 21, the first scanning galvanometer 22, and the first focusing field lens 23 in sequence and reaches the surface of the component to be polished. The diameter of the focused spot is 15 - 30μm, and the peak power density can reach 1×10 12 W / cm 2 or above, and the energy distribution form of the laser spot is a flat-top distribution;

[0085] The maximum average power of the mid-infrared continuous fiber laser in the second laser polishing module 3 is 1000 W. The laser emitted by it passes through the second collimating and beam expanding mirror 31, the second scanning galvanometer 32, and the second focusing field lens 33 in sequence and then reaches the surface of the component to be polished. The diameter of the focused spot is 50 - 300 μm, and the peak power density can reach 1×10 6 W / cm 2 or more, and the energy distribution form of the laser spot is a flat-top distribution;

[0086] The maximum average power of the mid-infrared nanosecond fiber laser in the third laser polishing module 4 is 1000 W. The laser emitted by it passes through the third collimating and beam expanding mirror 41, the third scanning galvanometer 42, and the third focusing field lens 43 in sequence and then reaches the surface of the component to be polished. The diameter of the focused spot is 800 - 1200 μm, and the peak power density can reach 1×10 8 W / cm 2 or more, and the energy distribution form of the laser spot is a flat-top distribution;

[0087] The focal lengths of the lasers emitted by the first laser polishing module 2, the second laser polishing module 3, and the third laser polishing module 4 are 160 mm. When an asynchronous composite polishing device for coupling multiple lasers is used for asynchronous composite polishing of multiple lasers, each laser polishing is completed at the laser focal plane.

[0088] It should be noted that in the embodiments of the present invention, the optical path designs of the first laser polishing module 2, the second laser polishing module 3, and the third laser polishing module 4 are completely independent, and different process parameters can be selected according to the material of the component to be polished to meet different requirements.

[0089] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually in accordance with the conditions recommended by the manufacturers.

[0090] Embodiment

[0091] In this embodiment, laser polishing is performed on a Stavax-ESR martensitic die steel as the component to be polished

[0092] 1.1. Detect the surface roughness Sa of the Stavax-ESR martensitic die steel. Its original surface roughness Sa is 6.2 μm, and its original surface three-dimensional morphology is as shown in Figure 7 (a) in it;

[0093] 1.2. The surface of the component to be polished is polished using infrared picosecond laser, with a pulse width of 8 ps, a laser power of 20 W, a scanning speed of 1000 mm / s, a track overlap rate of 95%, a repetition frequency of 400 kHz, a focused spot diameter of 20 μm, and the polishing path is in the shape of a "bow". It is polished 4 times, and after each polishing, the component to be polished is rotated 90°. After this step of polishing, the three-dimensional surface structure is as shown in Figure 7 shown in (b) of

[0094] 1.3. The surface of the component to be polished is polished using the infrared continuous laser, with a laser power of 200 W, a scanning speed of 500 mm / s, a track overlap rate of 90%, a focused spot diameter of 100 μm, and the polishing path is in the shape of a "bow". It is polished 4 times, and after each polishing, the component to be polished is rotated 90°. After this step of polishing, the three-dimensional surface structure is as shown in Figure 7 shown in (c) of

[0095] 1.4. The surface of the component to be polished is polished using infrared nanosecond laser, with a pulse width of 100 ns, a laser power of 350 W, a scanning speed of 1000 mm / s, a track overlap rate of 90%, a repetition frequency of 10 kHz, a focused spot diameter of 1000 μm, and the polishing path is in the shape of a "bow". It is polished 4 times, and after each polishing, the component to be polished is rotated 90°. After this step of polishing, the three-dimensional surface structure is as shown in Figure 7 shown in (d) of

[0096] 1.5. After the polishing in steps 1.2 - 1.4, the surface roughness Sa of the Stavax-ESR martensitic die steel is reduced to 74 nm, and the surface roughness reduction rate reaches 98.8%.

[0097] Figure 8 is the macroscopic effect diagram obtained after the Stavax-ESR martensitic die steel is polished by the asynchronous composite polishing method coupling multiple lasers in this embodiment. Among them, Figure 8 the left shaded part is not polished, and the right smooth part is polished. From Figure 8 it can be seen that after the polishing in this embodiment, the Stavax-ESR martensitic die steel shows excellent reflective effect and basically presents a mirror-like shape.

[0098] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. An asynchronous composite polishing method for coupling multiple lasers, characterized in that Including the following steps: Step S1: Detect the surface roughness of the component to be polished to obtain a first detection result; Step S2: Polish the component to be polished according to the first detection result to obtain a polished component; When the surface roughness of the component to be polished is greater than or equal to 3 μm, use ultrafast laser to polish the surface of the component to be polished, and then, in a protective atmosphere, use continuous laser and short-pulse laser to polish the component to be polished in sequence; when the surface roughness of the component to be polished is greater than or equal to 0.5 μm and less than 3 μm, use the continuous laser and the short-pulse laser to polish the component to be polished in sequence in a protective atmosphere; when the surface roughness of the component to be polished is less than 0.5 μm, use the short-pulse laser to polish the component to be polished in a protective atmosphere; Step S3: Detect the surface roughness of the polished component to obtain a second detection result; Step S4: Make a judgment according to the second detection result and the preset roughness. If the requirement of the preset roughness is not met, re-polish the polished component by laser.

2. The asynchronous composite polishing method for coupling multiple lasers according to claim 1, characterized in that In step S2, using ultrafast laser to polish the surface of the component to be polished includes: Using infrared picosecond laser to polish the surface of the component to be polished, with a pulse width of 8 ps, a laser power of 20 W, a scanning speed of 1000 mm / s, a track overlap rate of 95%, a repetition frequency of 400 kHz, a focused spot diameter of 20 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

3. The asynchronous composite polishing method for coupling multiple lasers according to claim 2, characterized in that In step S2, the method of polishing with continuous laser includes: Using infrared continuous laser to polish the surface of the component to be polished, with a laser power of 200 W, a scanning speed of 500 mm / s, a track overlap rate of 90%, a focused spot diameter of 100 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

4. The asynchronous composite polishing method for coupling multiple lasers according to claim 3, characterized in that In step S2, the method of polishing with short-pulse laser includes: Using infrared nanosecond laser to polish the surface of the component to be polished, with a pulse width of 100 ns, a laser power of 350 W, a scanning speed of 1000 mm / s, a track overlap rate of 90%, a repetition frequency of 10 kHz, a focused spot diameter of 1000 μm, a polishing path of "bow" shape, polishing 3 - 5 times, and rotating the component to be polished 90° after each polishing.

5. An asynchronous composite polishing device for coupling multiple lasers, used to implement the asynchronous composite polishing method for coupling multiple lasers according to any one of claims 1-4, characterized in that Including a base (1), a first laser polishing module (2), a second laser polishing module (3), a third laser polishing module (4) and a surface roughness detection module (5), the first laser polishing module (2), the second laser polishing module (3), the third laser polishing module (4) and the surface roughness detection module (5) are all located above the base (1); Among them, the first laser polishing module (2) is used to achieve ultrafast laser polishing; The second laser polishing module (3) is used to achieve continuous laser polishing; The third laser polishing module (4) is used to achieve short-pulse laser polishing; The surface roughness detection module (5) is used to detect the surface roughness of the component to be polished.

6. The asynchronous composite polishing device for coupling multiple lasers according to claim 5, characterized in that It further includes a cavity (6), an air inlet valve (61) and an air outlet valve (62) are arranged on the cavity (6), and the first laser polishing module (2), the second laser polishing module (3), the third laser polishing module (4) and the surface roughness detection module (5) are all located inside the cavity (6).

7. The asynchronous composite polishing device for coupling multiple lasers according to claim 6, characterized in that It further includes a gas sensor (7), the gas sensor (7) is located inside the cavity (6) and is used to detect the oxygen concentration inside the cavity (6).

8. The asynchronous composite polishing device for coupling multiple lasers according to claim 5, characterized in that It further includes a displacement stage (8), the displacement stage (8) is arranged on the base (1), and the displacement stage (8) is used to drive the component to be polished to move below the first laser polishing module (2), the second laser polishing module (3), the third laser polishing module (4) and the surface roughness detection module (5).

9. The asynchronous composite polishing device for coupling multiple lasers according to claim 5, characterized in that The first laser polishing module (2) includes an infrared picosecond fiber laser, a first collimating and beam expanding mirror (21), a first scanning galvanometer (22) and a first focusing field lens (23). The infrared picosecond laser emitted by the infrared picosecond fiber laser passes through the first collimating and beam expanding mirror (21), the first scanning galvanometer (22) and the first focusing field lens (23) in sequence to form a first focused spot; the second laser polishing module (3) includes an infrared continuous fiber laser, a second collimating and beam expanding mirror (31), a second scanning galvanometer (32) and a second focusing field lens (33). The infrared continuous laser emitted by the infrared continuous fiber laser passes through the second collimating and beam expanding mirror (31), the second scanning galvanometer (32) and the second focusing field lens (33) in sequence to form a second focused spot; the third laser polishing module (4) includes an infrared nanosecond fiber laser, a third collimating and beam expanding mirror (41), a third scanning galvanometer (42) and a third focusing field lens (43). The infrared nanosecond laser emitted by the infrared nanosecond fiber laser passes through the third collimating and beam expanding mirror (41), the third scanning galvanometer (42) and the third focusing field lens (43) in sequence to form a third focused spot.

10. The asynchronous composite polishing device for coupling multiple lasers according to claim 5, characterized in that The surface roughness detection module (5) includes a laser confocal microscope or a roughness measuring instrument.

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