Water-jet guided laser processing surface quality improvement process

Abstract

The invention discloses a water-jet guided laser processing surface quality improvement process, which can effectively reduce heat accumulation of a single area by adopting segmented processing, staggered path or spiral track to disperse heat input, quicken slag cooling and facilitate removal, avoid an interface or a stress concentration area to reduce thermal stress concentration, and improve the surface quality of the water-jet guided laser processing surface. The accumulation of local thermal gradient can be reduced by using dislocation processing or a multi-direction alternating path, the surface temperature gradient is effectively reduced through dynamic cooling, the thermal stress can be reduced, and the initiation and extension of cracks can be inhibited. In addition, the interface thermal expansion difference can be reduced through water spraying cooling, and therefore the layering possibility is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of water-conducting laser processing, in particular to a process for improving the surface quality of water-conducting laser processing. Background Art

[0002] Water-guided laser technology is a green, efficient and precision processing technology. Its principle is to couple a high-energy laser beam into a fine water jet, and the water jet guides the laser to the surface of the workpiece to achieve precision thermal processing such as cutting, drilling or grooving of the workpiece. At the same time, the water jet can take away excess heat and residue. Therefore, water-guided laser technology can achieve precise control of high-density energy in the "cold and hot source" mode, and then obtain ultra-precise, efficient and high-quality incisions, which is very suitable for fine processing of materials such as high-temperature alloys, wafers and carbon fibers, and processing of parts of biomedical devices.

[0003] Water-conducting laser processing combines the high energy density of the laser with the rapid cooling effect of the water jet, which can efficiently remove materials while ensuring that the processed surface has excellent cleanliness and taper-free processing quality. Therefore, this technology has gradually become an important choice in the field of precision processing, especially for high-demand materials such as industrial ceramics and semiconductor substrates. However, when processing certain composite materials (such as carbon fiber reinforced plastic CFRP) or multiphase materials with significant differences in material properties, the water-conducting laser processing process still faces significant technical challenges, especially the heat-affected zone (HAZ) problem. Due to the local accumulation of laser energy and differences in material thermal conductivity, a large heat-affected zone may appear on the processed surface, resulting in local material performance degradation, microstructural changes and even cracks, which directly affects the processing quality and component life.

[0004] For example, Chinese patent CN 117620223 A discloses a device and method for water-conducting laser assisted laser directional energy deposition. The water-conducting laser processing system generates a laser jet beam to process and generate microstructures in the deposition area on the surface of the substrate or the surface of the workpiece with high-reflective metal materials; the laser directional energy deposition system deposits high-reflective metal materials in the deposition area and manufactures the workpiece by layer-by-layer deposition; the workbench drives the substrate to lift the workpiece during the processing of the workpiece; the control system is respectively connected to the laser directional energy deposition system, the water-conducting laser processing system and the workbench, and alternately controls the connected components. The microstructure is generated on the surface of the workpiece by water-conducting laser, and the laser is reflected and absorbed multiple times inside the microstructure, which significantly improves the laser absorption rate, surface roughness and wettability, and reduces the thermal conductivity of the material surface. Although this technical solution solves the problems of low laser absorption rate, excessive heat conduction, poor wettability and poor molten pool spreading in the prior art, in actual operation, the heat generated by the fixed water-conducting laser processing system in the technical solution during processing cannot be taken away as quickly as possible, and the heat-affected zone cannot be reduced, which can easily cause the material to be delaminated, cracked or mechanical properties to deteriorate due to local overheating, resulting in low production efficiency and high defective rate. Heat concentration will cause the heat-affected zone to expand, triggering local degradation and delamination of the composite matrix or reinforcement, and even leading to a decrease in mechanical properties.

[0005] Another example is a circular water curtain composite water-guided laser processing device and method disclosed in Chinese patent CN 117086478 A, which includes a light-water coupling device, an annular water jet device, a nozzle and an annular nozzle. A nozzle is arranged at the lower end of the light-water coupling device, an annular nozzle is arranged on the annular water jet device, and the nozzle is coaxially arranged in the annular nozzle. The light-water coupling device is used to couple the laser beam with high-pressure water and then eject a light-guided water jet from the nozzle. The annular water jet device is used to eject high-pressure water from the annular nozzle to form an annular water curtain covering the light-guided water jet. It is mainly used for precision thermal processing such as cutting, drilling and grooving. Although this technical solution can extend and stabilize the length of the water jet during processing, it cannot effectively remove the slag and particles generated during processing, and is prone to secondary pollution. The product surface is rough and prone to ablation risks, and it is impossible to avoid damage to the material under high temperature. Summary of the invention

[0006] Purpose of the invention: In order to solve the shortcomings of the existing technology, the present invention provides a water-conducting laser processing surface quality improvement process, which makes the heat distribution more uniform through diversified processing trajectories to avoid local overheating problems, and significantly improves the heat-affected zone on the surface of the material through the combination of multiple trajectories and surface heat conduction devices, ensuring processing accuracy and surface integrity, and providing a new solution for the application of water-conducting laser technology in composite material processing.

[0007] Technical solution: In order to achieve the above purpose, the present invention provides a water-conducting laser processing surface quality improvement process, which includes the following specific steps:

[0008] Step 1: Clean the surface of the material to be processed according to the material characteristics and keep the surface of the material to be processed dry;

[0009] Step 2: Set and output the processing trajectory code on the water-guided laser processing equipment;

[0010] Step 3: When processing the material, use the water spray device on the water-guided laser processing equipment to direct water flow to the surface of the material to reduce the local temperature of the material surface and reduce thermal damage during the processing;

[0011] Step 4: Process the material to be processed according to the preset processing trajectory, and cut along the surface edge of the part using contour cutting;

[0012] Step 5: After the material processing is completed, the finished product is taken out from the fixture, and the slag on the surface of the finished product is removed by the flow of water on the water spray device;

[0013] Step 6: Place the cut material under an optical microscope and count the ablation conditions to adjust the processing parameters and further improve the surface quality.

[0014] As a further preferred embodiment of the present invention, in step 1, the surface of the water-insoluble material is cleaned by ultrasonic wave.

[0015] As a further preferred embodiment of the present invention, in step one, the surface of the material to be processed is kept dry by drying, blowing or natural air drying.

[0016] As a further preferred embodiment of the present invention, in step 2, UG software is used to output the processing trajectory code on the water-guided laser processing equipment.

[0017] As a further preferred embodiment of the present invention, in step three, the water spraying device introduces water flow to the surface of the material so that the temperature of the surface of the material is limited to 40°C-80°C.

[0018] As a further preferred embodiment of the present invention, the water spray diameter of the water flow on the water spray device is 20mm-25mm, the water flow velocity is 18mm / s-22mm / s, and the water flow pressure is 10bar-12bar.

[0019] As a further preferred embodiment of the present invention, in step 4, the contour cutting is spiral cutting, segmented processing or staggered path.

[0020] As a further preferred embodiment of the present invention, in step six, a CCD camera is used to take pictures and measure, and the ablation situation is counted by x-eye app Design-expert statistical software.

[0021] Beneficial effects: Compared with the prior art, the water-conducting laser processing surface quality improvement process described in the present invention has the following advantages:

[0022] (1) By adopting segmented processing, staggered paths or spiral trajectories to disperse heat input, heat accumulation in a single area can be effectively reduced, while accelerating slag cooling and facilitating removal;

[0023] (2) During the processing, the staggered path and spiral processing trajectory are used to avoid interfaces or stress concentration areas, which can effectively reduce thermal stress concentration and reduce the risk of crack formation;

[0024] (3) Using offset processing or multi-directional alternating paths can reduce the accumulation of local thermal gradients;

[0025] (4) Combined with surface water spray cooling technology, it can quickly take away heat and inhibit heat diffusion, thereby reducing the heat affected zone. At the same time, the water flow can also clean the slag in the processing area, reduce the risk of ablation, and maintain surface integrity;

[0026] (5) Dynamic cooling can effectively reduce the surface temperature gradient, reduce thermal stress, and inhibit the initiation and expansion of cracks;

[0027] (6) Water spray cooling can reduce the difference in thermal expansion of the interface, thereby reducing the possibility of stratification. The water flow direction is concentrated and controllable, which can adapt to different processing requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] Step 1

[0032] Clean the surface of the material to be processed according to the material characteristics and keep it dry. Use ultrasonic waves to clean the surface of the water-insoluble material and keep it dry by drying.

[0033] Step 2

[0034] Set up on the water-conducting laser processing equipment and use UG software to output the processing trajectory code on the water-conducting laser processing equipment;

[0035] Step 3

[0036] When processing the material, the water spray device on the water-guided laser processing equipment is used to direct water flow to the material surface to reduce the local temperature of the material surface and reduce thermal damage during processing. The water spray device directs water flow to the material surface to limit and maintain the temperature of the material surface at 40°C. The water spray diameter of the water flow on the water spray device is 20mm, the water flow rate is 18mm / s, and the water flow pressure is 10bar.

[0037] Step 4

[0038] The material to be processed is processed according to the preset processing trajectory, and the spiral cutting method is used to cut along the surface edge of the part;

[0039] Step 5

[0040] After the material processing is completed, the finished product is taken out from the fixture, and the slag on the surface of the finished product is taken away by the flow of water on the water spray device;

[0041] Step 6

[0042] The cut material is placed under an optical microscope, photographed and measured using a CCD camera, and the x-eye app Design-expert statistical software is used to calculate the ablation situation to adjust the processing parameters and further improve the surface quality.

[0043] Example 2

[0044] Step 1

[0045] Clean the surface of the material to be processed according to the material characteristics and keep it dry. Use ultrasonic waves to clean the surface of the water-insoluble material and keep it dry by blowing it dry.

[0046] Step 2

[0047] Set up on the water-conducting laser processing equipment and use UG software to output the processing trajectory code on the water-conducting laser processing equipment;

[0048] Step 3

[0049] When processing the material, the water spray device on the water-guided laser processing equipment is used to direct water flow to the material surface to reduce the local temperature of the material surface and reduce thermal damage during processing. The water spray device directs water flow to the material surface to limit and maintain the temperature of the material surface at 60°C. The water spray diameter of the water flow on the water spray device is 22mm, the water flow rate is 20mm / s, and the water flow pressure is 11bar.

[0050] Step 4

[0051] Process the material to be processed according to the preset processing trajectory, and cut along the surface edge of the part using a staggered path;

[0052] Step 5

[0053] After the material processing is completed, the finished product is taken out from the fixture, and the slag on the surface of the finished product is taken away by the flow of water on the water spray device;

[0054] Step 6

[0055] The cut material is placed under an optical microscope, photographed and measured using a CCD camera, and the x-eye app Design-expert statistical software is used to calculate the ablation situation to adjust the processing parameters and further improve the surface quality.

[0056] Example 3

[0057] Step 1

[0058] Clean the surface of the material to be processed according to the material characteristics and keep it dry. Use ultrasonic waves to clean the surface of the water-insoluble material and keep it dry by natural air drying.

[0059] Step 2

[0060] Set up on the water-conducting laser processing equipment and use UG software to output the processing trajectory code on the water-conducting laser processing equipment;

[0061] Step 3

[0062] When processing the material, the water spray device on the water-guided laser processing equipment is used to direct water flow to the material surface to reduce the local temperature of the material surface and reduce thermal damage during processing. The water spray device directs water flow to the material surface to limit and maintain the temperature of the material surface at 80°C. The water spray diameter of the water flow on the water spray device is 25mm, the water flow rate is 22mm / s, and the water flow pressure is 12bar.

[0063] Step 4

[0064] Process the material to be processed according to the preset processing trajectory, and cut along the surface edge of the part using segmented processing;

[0065] Step 5

[0066] After the material processing is completed, the finished product is taken out from the fixture, and the slag on the surface of the finished product is taken away by the flow of water on the water spray device;

[0067] Step 6

[0068] The cut material is placed under an optical microscope, photographed and measured using a CCD camera, and the x-eye app Design-expert statistical software is used to calculate the ablation situation to adjust the processing parameters and further improve the surface quality.

[0069] The present invention quickly removes the heat generated during the processing, reduces the heat affected zone (HAZ), and avoids delamination, cracking, or mechanical property degradation of the material due to local overheating. The water spray device can effectively remove the slag and particles generated during processing, reduce secondary pollution, improve surface finish, reduce the risk of ablation, and avoid material damage under high temperature. Dynamic cooling reduces the temperature gradient on the workpiece surface, thereby reducing thermal stress and effectively inhibiting the initiation and expansion of cracks. The present invention not only optimizes economic benefits, but also provides reliable support for the processing of difficult materials, and is in line with the development trend of green manufacturing and precision processing.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for improving surface quality of water-conducting laser machining, characterized in that: It includes the following steps: Step 1 Clean the surface of the material to be processed according to the material characteristics and keep the surface of the material to be processed dry; Step 2 Set and output the processing trajectory code on the water-conducting laser processing equipment; Step 3 When processing the material, use the water spray device on the water-guided laser processing equipment to direct the water flow onto the material surface; Step 4 Process the material to be processed according to the preset processing trajectory, and cut along the surface edge of the part using contour cutting; Step 5 After the material processing is completed, the finished product is taken out from the fixture, and the slag on the surface of the finished product is taken away by the flow of water on the water spray device; Step 6 The cut material is placed under an optical microscope to count the ablation conditions in order to adjust the processing parameters and further improve the surface quality.

2. A water-conducting laser machining surface quality improvement process according to claim 1, characterized in that: In step 1, the surface of the water-insoluble material is cleaned by ultrasonic wave.

3. The water-conducting laser machining surface quality improvement process according to claim 1, characterized in that: In step one, the surface of the material to be processed is kept dry by drying, blowing, or air drying.

4. The water-conducting laser machining surface quality improvement process according to claim 1, characterized in that: In step 2, UG software is used to output the processing trajectory code on the water-guided laser processing equipment.

5. The water-conducting laser machining surface quality improvement process according to claim 1, characterized in that: In step three, the water spray device directs water flow to the surface of the material so that the temperature of the surface of the material is limited to 40°C to 80°C.

6. A water-conducting laser machining surface quality improvement process according to claim 5, characterized in that: The water spraying diameter of the water flow on the water spraying device is 20mm-25mm, the water flow velocity is 18mm / s-22mm / s, and the water flow pressure is 10bar-12bar.

7. The process for improving surface quality of water-conducting laser machining according to claim 1, characterized in that: In step 4, the contour cutting is spiral cutting, segmented processing or staggered path.

8. The water-conducting laser machining surface quality improvement process according to claim 1, characterized in that: In step six, the CCD camera is used to take pictures and measure, and the x-eye app Design-expert statistical software is used to calculate the ablation situation.

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