Underwater femtosecond laser-assisted water and abrasive particle fluid dynamic pressure effect polishing test device and working method thereof

Abstract

The invention discloses an underwater femtosecond laser assisted water and abrasive particle fluid dynamic pressure effect polishing test device and a working method thereof. The underwater femtosecond laser assisted water and abrasive particle fluid dynamic pressure effect polishing test device comprises an abrasive particle stirring and mixing mechanism, a pressure control mechanism, a synchronous monitoring mechanism, a light window sealing mechanism, a convergence wedge control mechanism and a machine shell. The underwater femtosecond laser polishing device is suitable for materials such as semiconductors, metal and ceramics, underwater femtosecond laser machining can be adopted, the surface of a workpiece can be polished with different effects by controlling and changing the flow speed of abrasive particle flow and the angle of the convergence wedge through pressure and the convergence wedge, and efficient machining of polishing while irradiating on the workpiece is achieved.

Description

Technical Field

[0002] The present invention belongs to the technical field of laser processing and polishing machines, and particularly relates to an underwater femtosecond laser-assisted hydrodynamic effect polishing test device of water and abrasive grains and its working method. Background Art

[0003] With the continuous improvement of the requirements for the processing accuracy and quality of material surfaces in modern industry, traditional mechanical processing methods are difficult to meet the needs of certain high-precision and high-surface-quality requirements; in recent years, laser processing technology has gradually become an important means of material surface processing due to its advantages such as non-contact, high precision, and low heat-affected zone. However, single laser processing still has limitations in terms of material removal efficiency and surface quality in some cases.

[0004] The underwater femtosecond laser-assisted hydrodynamic effect polishing test device of water and abrasive grains, as a new type of composite processing technology, combines the hydrodynamic effect and the mechanical removal effect of abrasive flow; by introducing the hydrodynamic effect during femtosecond laser processing, this technology can significantly improve the material removal efficiency and surface quality.

[0005] However, there is currently a lack of a test device on the market that can accurately control parameters such as fluid pressure, abrasive flow mixing ratio, and abrasive grain size, which limits the research on the synergistic effect of femtosecond laser and hydrodynamic effect. Existing test devices also have deficiencies in aspects such as pressure control, abrasive stirring and mixing, and optical window sealing, making it difficult to achieve precise monitoring and control of the processing process. Therefore, developing a new type of underwater femtosecond laser-assisted hydrodynamic effect polishing test device of water and abrasive grains, which can achieve precise control and research on the synergistic effect of femtosecond laser and hydrodynamic effect, has important theoretical and practical significance. This device will provide strong support for studying the matching relationship between femtosecond laser and parameters such as fluid pressure, water-abrasive flow mixing ratio, and abrasive grain size, and promote the development of precision processing technology. Summary of the Invention

[0006] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide an underwater femtosecond laser-assisted hydrodynamic effect polishing test device of water and abrasive grains and its working method, which can significantly improve the material removal efficiency and surface quality.

[0007] The embodiments of the present invention are achieved through the following technical solutions: An underwater femtosecond laser-assisted hydrodynamic effect polishing test device of water and abrasive grains, characterized in that: it includes a machine shell and an abrasive stirring and mixing mechanism, a pressure control mechanism, a synchronous monitoring mechanism, an optical window sealing mechanism, and a convergence wedge control mechanism provided on the machine shell; The abrasive flow stirring and mixing mechanism includes an abrasive flow feed pipe, an abrasive flow stirrer, a mixing pipe, a feed hose, an abrasive discharge pipe, and a fluid discharge pipe; the abrasive flow feed pipe is fixed to the left side of the machine housing and its first end extends into the machine housing, the second end of the abrasive flow feed pipe is fixedly connected to the output end of the abrasive flow stirrer located above the abrasive flow feed pipe, the output end of the mixing pipe is fixedly connected to the upper input end of the abrasive flow stirrer, the lower outlet of the feed hose is connected to the upper inlet of the mixing pipe, and the lower ends of the abrasive discharge pipe and the fluid discharge pipe are respectively connected to the two inlets at the upper end of the feed hose; The pressure control mechanism includes a hydraulic pipe connected to the upper right side of the abrasive flow feed pipe and a pressure control piston installed inside the hydraulic pipe; The synchronous monitoring mechanism includes a monitor assembly installed on the left side of the machine housing, a spectral signal monitor, an acoustic emission signal monitor, and a visual signal monitor installed on the monitor assembly; The optical window sealing mechanism includes an optical window sealing cover, a laser optical window, and a femtosecond laser; the laser optical window is fixed at the exact center of the upper side of the machine housing, the femtosecond laser is incident into the machine housing from the laser optical window, and the optical window sealing cover can be covered above the laser optical window to control whether the femtosecond laser is incident into the machine housing; The convergent wedge control mechanism includes a control motor, a shaft connected to the output end of the control motor, a processing platform, and a platform base; the control motor is fixed to the rear side plate of the machine housing, the platform base is connected to the output end of the control motor through the shaft, the processing platform is used to hold the silicon carbide wafer to be processed, and the processing platform is installed on the platform base and is located directly below the femtosecond laser.

[0008] Preferably, the above-mentioned spectral signal monitor, acoustic emission signal monitor, and visual signal monitor are installed in the middle position of the monitor assembly from top to bottom in sequence.

[0009] Preferably, the above-mentioned monitor assembly and the abrasive flow feed pipe are installed on the same vertical plane.

[0010] Preferably, an abrasive flow recovery pipe is connected to the right side of the machine housing for the recovery and recycling of the abrasive flow.

[0011] Preferably, the above-mentioned abrasive stirring and mixing mechanism can control the mixing of abrasives and water in different proportions; the pressure control mechanism can change the pressure to control the flow rate of the abrasive flow; the synchronous monitoring mechanism can realize the real-time monitoring of spectral signals, acoustic emission signals, and visual signals; the optical window sealing mechanism can realize the use and closing of the femtosecond laser; the convergent wedge control mechanism can change the angle of the processing platform through the control motor to realize the change of the hydrodynamic effect and the polishing effect.

[0012] The working method of the underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive fluid of the present invention is characterized in that: When polishing a silicon carbide wafer to be polished, the silicon carbide wafer to be polished is placed and fixed above the processing platform. Appropriate amounts of abrasive grains and water are respectively placed in the abrasive grain feeding pipe and the fluid feeding pipe. The specific feeding amounts are determined according to the ratio. The abrasive grains and water enter the feeding hose, first go to the mixing pipe for preliminary mixing, then enter the abrasive flow stirrer for sufficient stirring and mixing, and finally enter the casing through the abrasive flow feeding pipe. The flow rate of the abrasive flow entering the casing is changed by the pressure control piston in the hydraulic pipe by changing the pressure in the pipe; the femtosecond laser is emitted into the casing from the laser light window, so as to perform femtosecond laser modification while polishing the silicon carbide wafer to achieve efficiency increase; the spectral signal monitor, acoustic emission signal monitor and visual signal monitor in the synchronous monitoring mechanism respectively perform real-time monitoring on the surface state, physical properties during the processing and macroscopic morphology of the silicon carbide wafer. The spectral signal monitor can judge the changes in the chemical composition and microscopic structure damage on the surface of the silicon carbide wafer by analyzing the changes in the reflection spectrum. The acoustic emission signal monitor can capture the tiny acoustic wave signals generated during the processing, so as to monitor the stress distribution and crack initiation on the wafer surface in real time. The visual signal monitor can observe the morphology of the silicon carbide wafer in real time, including information such as surface flatness, scratches, and particle residues; the rotation of the control motor control shaft drives the platform base and the processing platform to rotate, so that a certain convergent wedge angle is formed between the processing platform and the casing, which can improve the uniformity and consistency of polishing. Finally, the abrasive flow is recycled through the abrasive flow recovery pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is an isometric schematic diagram of the overall structure of the present invention; Figure 2 is a cross-sectional schematic diagram of the overall structure of the present invention; Figure 3 is a schematic diagram of the convergent wedge control mechanism of the present invention; In the figure: 1 casing; 2 abrasive flow feeding pipe; 3 abrasive flow stirrer; 4 mixing pipe; 5 feeding hose; 6 abrasive grain feeding pipe; 7 fluid feeding pipe; 8 pressure control piston; 9 hydraulic pipe; 10 light window sealing cover; 11 laser light window; 12 abrasive flow recovery pipe; 13 monitor assembly; 14 spectral signal monitor; 15 acoustic emission signal monitor; 16 visual signal monitor; 17 femtosecond laser; 18 control motor; 19 processing platform; 20 platform base; 21 shaft. DETAILED DESCRIPTION OF THE INVENTION

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0017] The underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive grains of the present invention includes a machine housing 1 and an abrasive grain stirring and mixing mechanism, a pressure control mechanism, a synchronous monitoring mechanism, an optical window sealing mechanism, and a converging wedge control mechanism provided on the machine housing 1.

[0018] Among them, the abrasive grain flow stirring and mixing mechanism includes an abrasive grain flow inlet pipe 2, an abrasive grain flow stirrer 3, a mixing pipe 4, a feed hose 5, an abrasive grain discharge pipe 6, and a fluid discharge pipe 7; the abrasive grain flow inlet pipe 2 is fixed on the left side of the machine housing 1 and its first end extends into the machine housing 1, and the second end of the abrasive grain flow inlet pipe 2 is fixedly connected to the output end of the abrasive grain flow stirrer 3 located above the abrasive grain flow inlet pipe 2. The output end of the mixing pipe 4 is fixedly connected to the upper input end of the abrasive grain flow stirrer 3 (this abrasive grain flow stirrer 3 can be a magnetic stirrer, a magnetic stirrer agitator, etc.). The lower outlet of the feed hose 5 (in a U shape) is connected to the upper inlet of the mixing pipe 4, and the lower ends of the abrasive grain discharge pipe 6 and the fluid discharge pipe 7 are respectively connected to the two inlets at the upper end of the feed hose 5. Abrasives are put in through the inlet of the abrasive grain discharge pipe 6, and fluid (such as water) is put in through the inlet of the fluid discharge pipe 7.

[0019] Among them, the pressure control mechanism includes a hydraulic pipe 9 connected to the upper right side of the abrasive grain flow inlet pipe 2 and a pressure control piston 8 installed inside the hydraulic pipe 9. This pressure control piston 8 can be an air pump with adjustable pressure.

[0020] Among them, the synchronous monitoring mechanism includes a monitor assembly 13 installed on the left side of the machine housing 1, a spectral signal monitor 14, an acoustic emission signal monitor 15, and a visual signal monitor 16 installed on the monitor assembly 13 (the spectral signal monitor 14, the acoustic emission signal monitor 15, and the visual signal monitor 16 are commercially available components, and their specific structures and working principles will not be elaborated here); the monitor assembly 13 and the abrasive grain flow inlet pipe 2 are installed on the same vertical plane, and the spectral signal monitor 14, the acoustic emission signal monitor 15, and the visual signal monitor 16 are installed in the middle position of the monitor assembly 13 from top to bottom in sequence.

[0021] Among them, the optical window sealing mechanism includes an optical window sealing cover 10, a laser optical window 11, and a femtosecond laser 17; the laser optical window 11 is fixedly covered at the exact center of the upper side of the machine housing 1, and the femtosecond laser 17 is emitted into the interior of the machine housing through the laser optical window 11. The optical window sealing cover 10 can be covered above the laser optical window to control whether the femtosecond laser is emitted into the machine housing; The convergence wedge control mechanism includes a control motor 18, a shaft 21 connected to the output end of the control motor, a processing platform 19, and a platform base 20; the control motor 18 is fixed on the rear side plate of the machine housing 1, the platform base 20 is connected to the output end of the control motor 18 through the shaft 21, the processing platform 19 is used to hold the silicon carbide wafer to be processed, the processing platform 19 is installed on the platform base 20 and is located directly below the femtosecond laser 17; by the action of the control motor 18, the swing of the silicon carbide wafer can be realized to adjust the angle.

[0022] A abrasive flow recovery pipe 12 is connected to the right side of the machine housing 1 for the recycling of abrasive flow.

[0023] The usage method of the device of the present invention: When polishing a silicon carbide wafer to be polished, place the silicon carbide wafer to be polished above the processing platform 19 and fix it. Put appropriate amounts of abrasive grains and water into the abrasive grain feeding pipe 6 and the fluid feeding pipe 7 respectively. The specific feeding amounts are determined according to the ratio. The abrasive grains and water enter the feeding hose 5, first enter the mixing pipe 4 for preliminary mixing, then enter the abrasive flow stirrer 3 for sufficient stirring and mixing, and finally enter the machine housing 1 through the abrasive flow feeding pipe 2. The abrasive flow changes the flow rate entering the machine housing 1 by changing the pressure in the pipe through the pressure control piston 8 in the hydraulic pipe 9; the femtosecond laser 17 is emitted into the machine housing 1 from the laser light window 11, so as to perform femtosecond laser modification while polishing the silicon carbide wafer to achieve efficiency increase; the spectral signal monitor 14, the acoustic emission signal monitor 15, and the visual signal monitor 16 in the synchronous monitoring mechanism respectively perform real-time monitoring on the surface state of the silicon carbide wafer, the physical properties during the processing, and the macroscopic morphology. The spectral signal monitor 14 can judge the changes in the chemical composition and microstructural damage on the surface of the silicon carbide wafer by analyzing the changes in the reflected spectrum. The acoustic emission signal monitor 15 can capture the tiny acoustic wave signals generated during the processing, so as to monitor the stress distribution and crack initiation on the wafer surface in real time. The visual signal monitor 16 can perform real-time observation on the morphology of the silicon carbide wafer, including information such as surface flatness, scratches, and particle residues; the control motor 18 controls the rotation of the shaft 21 to drive the platform base 20 and the processing platform 19 to rotate, so that the processing platform 19 forms a certain convergence wedge angle with the machine housing, which can improve the uniformity and consistency of polishing. Finally, the abrasive flow is recycled through the abrasive flow recovery pipe 12.

[0024] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive particles, characterized in that: It includes a housing (1) and an abrasive stirring and mixing mechanism, a pressure control mechanism, a synchronous monitoring mechanism, an optical window sealing mechanism, and a convergence wedge control mechanism provided on the housing; The abrasive flow stirring and mixing mechanism includes an abrasive flow feed pipe (2), an abrasive flow stirrer (3), a mixing pipe (4), a feed hose (5), an abrasive discharge pipe (6), and a fluid discharge pipe (7); the abrasive flow feed pipe (2) is fixed to the left side of the housing (1) and its first end extends into the housing (1). The second end of the abrasive flow feed pipe (2) is fixedly connected to the output end of the abrasive flow stirrer (3) located above the abrasive flow feed pipe (2). The output end of the mixing pipe (4) is fixedly connected to the upper input end of the abrasive flow stirrer (3). The lower outlet of the feed hose (5) is connected to the upper inlet of the mixing pipe (4). The lower ends of the abrasive discharge pipe (6) and the fluid discharge pipe (7) are respectively connected to the two inlets at the upper end of the feed hose (5); The pressure control mechanism includes a hydraulic pipe (9) connected to the upper right side of the abrasive flow feed pipe (2) and a pressure control piston (8) installed inside the hydraulic pipe (9); The synchronous monitoring mechanism includes a monitor assembly (13) installed on the left side of the housing (1), a spectral signal monitor (14), an acoustic emission signal monitor (15), and a visual signal monitor (16) installed on the monitor assembly (13); The optical window sealing mechanism includes an optical window sealing cover (10), a laser optical window (11), and a femtosecond laser (17); the laser optical window (11) is fixed at the exact center of the upper side of the housing (1). The femtosecond laser (17) is emitted into the housing through the laser optical window (11). The optical window sealing cover (10) can cover the laser optical window to control whether the femtosecond laser is emitted into the housing; The convergence wedge control mechanism includes a control motor (18), a shaft (21) connected to the output end of the control motor, a processing platform (19), and a platform base (20); the control motor (18) is fixed to the rear side plate of the housing (1). The platform base (20) is connected to the output end of the control motor (18) through the shaft (21). The processing platform (19) is used to hold the silicon carbide wafer to be processed. The processing platform (19) is installed on the platform base (20) and is located directly below the femtosecond laser (17).

2. The underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive grains according to claim 1, wherein: The spectral signal monitor (14), the acoustic emission signal monitor (15), and the visual signal monitor (16) are installed in the middle position of the monitor assembly (13) from top to bottom in sequence.

3. The underwater femtosecond laser-assisted hydrodynamic effect polishing test device according to claim 1 or 2, characterized in that: The monitor assembly (13) and the abrasive flow feed pipe (2) are installed on the same vertical plane.

4. The underwater femtosecond laser-assisted hydrodynamic effect polishing test device according to claim 3, characterized in that: An abrasive flow recovery pipe (12) is connected to the right side of the housing (1) for the recovery and recycling of the abrasive flow.

5. The underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive according to claim 4, characterized in that: The abrasive stirring and mixing mechanism can control the mixing of abrasives and water in different proportions; the pressure control mechanism can change the pressure to control the flow rate of the abrasive flow; the synchronous monitoring mechanism can realize the real-time monitoring of spectral signals, acoustic emission signals, and visual signals; the optical window sealing mechanism can realize the use and shutdown of femtosecond lasers; the convergent wedge control mechanism can change the angle of the processing platform by controlling the motor, and realize the hydrodynamic effect to change the polishing effect.

6. A working method of an underwater femtosecond laser-assisted hydrodynamic effect polishing test device for water and abrasive, characterized in that: When polishing a silicon carbide wafer to be polished, the silicon carbide wafer to be polished is placed and fixed above the processing platform (19). Appropriate amounts of abrasives and water are respectively placed in the abrasive feeding pipe (6) and the fluid feeding pipe (7). The abrasives and water enter the feeding hose (5), first enter the mixing pipe (4) for preliminary mixing, then enter the abrasive flow stirrer (3) for sufficient stirring and mixing, and finally enter the casing (1) through the abrasive flow feeding pipe (2). The abrasive flow changes the flow rate entering the casing (1) by changing the pressure in the pipe through the pressure control piston (8) in the hydraulic pipe (9); the femtosecond laser (17) is emitted into the casing (1) from the laser optical window (11), so as to perform femtosecond laser modification while polishing the silicon carbide wafer to achieve efficiency increase; the spectral signal monitor (14), acoustic emission signal monitor (15), and visual signal monitor (16) in the synchronous monitoring mechanism respectively perform real-time monitoring on the surface state of the silicon carbide wafer, physical properties during the processing, and macroscopic morphology. The spectral signal monitor (14) can judge the chemical composition change and microscopic structure damage on the surface of the silicon carbide wafer by analyzing the change of the reflection spectrum. The acoustic emission signal monitor (15) can capture the tiny acoustic wave signals generated during the processing, so as to monitor the stress distribution and crack initiation on the wafer surface in real time. The visual signal monitor (16) can observe the morphology of the silicon carbide wafer in real time. The rotation of the control shaft (21) of the control motor (18) drives the platform base (20) and the processing platform (19) to rotate, so that the processing platform (19) forms a certain convergent wedge angle with the casing, which can improve the uniformity and consistency of polishing. Finally, the abrasive flow is recycled through the abrasive flow recovery pipe (12).

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