Vibration-assisted water-guided laser processing method

Abstract

The invention relates to a method which comprises the following steps: 1) putting a laser generator close to a water jet nozzle of a high-pressure water input device, spraying a high-pressure water jet through the water jet nozzle, focusing a laser beam into the water jet nozzle through the laser generator, and guiding the laser beam by the high-pressure water jet to form water-guided laser, the water-guided laser is emitted to the surface of the workpiece, and material removal machining is carried out; (2) the workpiece is fixed to a machine tool, the machine tool is controlled to move, and the workpiece and the water-guided laser generate relative displacement; (3) vibration generated by the vibration generating device is conducted to the workpiece, so that the workpiece generates vibration in the machining process; and (4) the laser generating device, the machine tool and the vibration generating device are cooperatively controlled through the control system to machine the workpiece. Compared with the prior art, the method has the beneficial effects of reducing the thickness of a recasting layer on the surface of a workpiece, improving the performance of a machined surface material and reducing thermal damage.

Description

Technical Field

[0001] The invention relates to the technical field of water-conducting laser processing, and in particular to a vibration-assisted water-conducting laser processing method. Background Art

[0002] Water-guided laser focuses the laser beam into a water jet nozzle. When the laser hits the interface between water and air, the light is emitted from the denser medium to the less dense medium, and the incident angle is greater than the critical angle. The laser is totally reflected at the interface and returns to the water. This reciprocating motion allows the laser to propagate in the water, so that the laser forms a straight line and shoots out, resulting in a longer working distance without defocusing the beam. This type of laser can be used to cut hard materials.

[0003] The removal of materials by water-conducting laser cutting is mainly through laser ablation that forms a molten pool, steam and plasma plume, but the water jet with high heat capacity can significantly affect the thermodynamics and kinetics of the ablated material. The flushing and cooling effect of the water flow after cutting can significantly reduce the recast layer and heat-affected zone on the surface of the cut material after laser cutting. Provide good heat control and clean up debris in the processing area.

[0004] However, a recast layer will still be formed on the surface after cutting. The recast layer on the surface of the material will affect the performance of the material, such as reducing the yield strength of the material. In addition, cracks are easily generated at the interface between the recast layer and the substrate, which greatly reduces the mechanical properties of the material. A thicker recast layer will also lead to higher stress concentration. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a vibration-assisted water-conducting laser processing method that reduces the thickness of the recast layer on the workpiece surface, improves the material properties of the processed surface and reduces thermal damage.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] As one aspect of the present invention, a vibration-assisted water-conducting laser processing method is provided, comprising the following steps:

[0008] Place the laser generator close to the water jet nozzle of the high-pressure water input device, spray high-pressure water jet through the water jet nozzle, and focus the laser beam into the water jet nozzle through the laser generator. The laser beam is guided by the high-pressure water jet to form a water-guided laser, and the water-guided laser is emitted to the surface of the workpiece to perform material removal processing;

[0009] Fix the workpiece on the machine tool, control the machine tool to move, and make the workpiece and the water-guided laser move relative to each other;

[0010] The vibration generated by the vibration generating device is transmitted to the workpiece, so that the workpiece vibrates during the processing;

[0011] The laser generating device, the machine tool and the vibration generating device are cooperatively controlled by the control system to process the workpiece.

[0012] Furthermore, the vibration generating device is a vibration generator, which transmits vibration to the workpiece through the clamping device, so that the workpiece generates high-frequency vibration in multi-dimensional directions.

[0013] Furthermore, when the water-guided laser irradiates the surface of the workpiece, the high temperature of the laser causes the metal surface to melt, thereby achieving material removal processing on the workpiece surface.

[0014] Furthermore, when the heat of the laser melts the metal surface, the melted part of the metal surface is vibrated into the water jet and then washed away by the water flow.

[0015] Furthermore, the machining process also includes an auxiliary gas module spraying gas onto the machining surface.

[0016] Furthermore, the laser generator, the high-pressure water input device and the auxiliary gas module work in coordination through a coupling device.

[0017] Furthermore, the control content of the control system includes water flow size, laser power, machine tool movement speed and displacement size, and vibration start and stop and power.

[0018] Furthermore, after the vibration-assisted water-guided laser processing is completed, the generated sewage is disposed of through a sewage treatment system.

[0019] As another aspect of the present invention, a vibration-assisted water-conducting laser processing system is provided, and the system executes the vibration-assisted water-conducting laser processing method.

[0020] At the same time, a vibration-assisted water-conducting laser processing device is provided, and the device is based on the vibration-assisted water-conducting laser processing system.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The present invention uses a vibration generating device to apply vibration to the workpiece while the workpiece is being processed by the water-guided laser. Before the surface material of the processed workpiece is melted by the laser but not solidified, the high-frequency vibration of the vibration generating device causes the molten metal material to enter the jet and be carried away by the high-speed water flow. The molten metal material is carried away, resulting in a reduction in the thickness of the recast layer on the surface of the workpiece after processing, thereby increasing the yield strength of the processed surface material, reducing the generation of cracks between the recast layer and the substrate, reducing stress concentration, and improving the service performance of the material.

[0023] (2) The present invention effectively reduces the heat-affected zone of the processed material through the cooling effect of water flow, provides good heat control, and reduces thermal damage to the material.

[0024] (3) The present invention improves the post-processing performance of the material through a relatively simple vibration coupling method, and has high practical processing feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an overall schematic diagram of the vibration-assisted water-conducting laser processing method;

[0026] Figure 2 It is a specific implementation diagram of the vibration-assisted water-conducting laser processing method;

[0027] Figure 3 Diagram of the interaction mechanism between water flow and remelted debris. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides a vibration-assisted water-conducting laser processing method, such as Figure 1 As shown, the system using the method includes a vibration generating device, a laser generating device and a coupling device.

[0031] The laser beam is focused into a water jet nozzle and guided by a laminar water jet, with total internal reflection at the water / air boundary. The material to be processed is fixed on the machine tool in a specific way, and the movement of the machine tool is used to remove the material. The vibration generated by the vibration generator is transmitted to the workpiece, causing the workpiece to generate high-frequency vibrations during the processing. The high-frequency vibration of the vibration sound generator causes the molten metal material to enter the jet and be carried away by the high-speed water flow. The molten metal material is carried away, resulting in a reduction in the thickness of the recast layer on the workpiece surface after processing, which increases the yield strength of the material on the processed surface, reduces the generation of cracks between the recast layer and the substrate, reduces stress concentration, and improves the service performance of the material.

[0032] The entire system is controlled by a control system, which can control the laser generator module, high-pressure water input module, auxiliary gas module, vibration generator module, machine tool and sewage treatment system. The laser generator, high-pressure water input and auxiliary gas modules generate water-conducting laser for cutting through coupling. The vibration generator applies vibration to the workpiece through the fixture. At the same time, the processing process is controlled by the movement of the machine tool. After the processing is completed, the generated sewage is treated through the sewage treatment system.

[0033] like Figure 2 As shown, during the process of water-guided laser cutting through the workpiece, the vibration generating device applies vibration to the workpiece, causing the workpiece to vibrate in multiple directions. The surface material is melted by the heating effect of the laser to form a fluid state that is easier to loosen. At the same time, the melted material on the surface is loosened by the vibration effect. The flushing of the water flow will also have an effect on the debris on the surface of the material, causing the melted material on the surface to be flushed or vibrated off before forming a recast layer, thereby reducing the thickness of the recast layer.

[0034] like Figure 3 As shown, before the surface material of the workpiece is melted by the laser but not solidified, it is in a state of fluid (jet)-fluid (molten metal)-solid (workpiece). Through the high-frequency vibration of the vibrating sound-generating device, the molten metal material enters the jet and is carried away by the high-speed water flow. The molten metal material is carried away, resulting in a reduction in the thickness of the recast layer on the workpiece surface after processing, which improves the yield strength of the processed surface material, reduces the generation of cracks between the recast layer and the substrate, reduces stress concentration, and improves the service performance of the material.

[0035] As a preferred embodiment, the present invention includes an auxiliary gas module for spraying gas onto the processing surface to accelerate the loosening process of the melted material.

[0036] As a preferred embodiment, the control content of the control system includes water flow size, laser power, machine tool movement speed and displacement size, and vibration start and stop and power.

[0037] As a preferred embodiment, a sewage treatment system is provided. During and after the vibration-assisted water-guided laser processing, the sewage containing the detached melted workpiece material generated after the high-pressure water input module is ejected through the sewage treatment system to be treated to avoid the sewage affecting subsequent processing.

[0038] As a preferred embodiment, the present invention couples the high-pressure water input module, the auxiliary gas module, and the laser generator module under the control of the control system to work in coordination, thereby improving the separation efficiency of the molten metal material from the processed surface.

[0039] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A vibration-assisted water-conducting laser processing method, characterized in that: The following steps are involved: Place the laser generator close to the water jet nozzle of the high-pressure water input device, spray high-pressure water jet through the water jet nozzle, and focus the laser beam into the water jet nozzle through the laser generator. The laser beam is guided by the high-pressure water jet to form a water-guided laser, and the water-guided laser is emitted to the surface of the workpiece to perform material removal processing; Fix the workpiece on the machine tool, control the machine tool to move, and make the workpiece and the water-guided laser move relative to each other; The vibration generated by the vibration generating device is transmitted to the workpiece, so that the workpiece vibrates during the processing; The laser generating device, the machine tool and the vibration generating device are cooperatively controlled by the control system to process the workpiece.

2. A vibration-assisted water-conducting laser processing method according to claim 1, characterized in that: The vibration generating device is a vibration generator, which transmits vibration to the workpiece through the clamping device, so that the workpiece generates high-frequency vibration in multi-dimensional directions.

3. The vibration-assisted water-conducting laser processing method according to claim 1, characterized in that: When the water-guided laser irradiates the workpiece surface, the high temperature of the laser causes the metal surface to melt, thereby achieving material removal processing on the workpiece surface.

4. The vibration-assisted water-conducting laser processing method according to claim 3, characterized in that: When the high temperature of the laser causes the metal surface to melt, the melted portion of the metal surface is vibrated and enters the water jet, and is then washed away by the water flow.

5. The vibration-assisted water-conducting laser processing method according to claim 1, characterized in that: The machining process also includes an auxiliary gas module spraying gas onto the machining surface.

6. The vibration-assisted water-conducting laser processing method according to claim 5, characterized in that: The laser generator, the high-pressure water input device and the auxiliary gas module work in coordination through a coupling device.

7. The vibration-assisted water-conducting laser processing method according to claim 1, characterized in that: The control content of the control system includes water flow size, laser power, machine tool moving speed and displacement size, and vibration start and stop and power.

8. The vibration-assisted water-conducting laser processing method according to claim 1, characterized in that: After the vibration-assisted water-guided laser processing is completed, the generated sewage is disposed of through a sewage treatment system.

9. A vibration-assisted water-guided laser processing system, characterized in that: The system executes a vibration-assisted water-conducting laser processing method according to any one of claims 1-8.

10. A vibration-assisted water-guided laser processing device, characterized in that: The device is based on a vibration-assisted water-guided laser machining system according to claim 9.

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