A method for processing a sidewall nanograting-microgroove composite texture and a tool holder device

Abstract

The application discloses a kind of side wall nanometer grating-micro groove composite texture processing method and tool holder device, belong to ultra-precision micro-nano functional surface manufacturing technical field.The application adopts stationary wave node switching type composite processing tool holder, utilizes ultrasonic amplitude transformer stationary wave characteristics, is fixed switching plate installation post-processing tool at zero amplitude stationary wave node, installs pre-processing tool at amplitude transformer output end, realizes the differential processing state of single tool holder pre-tool axial ultrasonic vibration, post-tool no vibration.During processing, pre-tool generates nanometer grating on groove side wall and groove bottom by intermittent cutting, post-tool is finely processed to groove bottom, removes groove bottom grating and retains side wall grating, and single pass can prepare side wall with nanometer grating, groove bottom super-smooth composite texture.The application process is high in integration, without secondary tool setting error, can be formed by processing once, improve processing efficiency, and is suitable for optical anti-counterfeiting, micro-fluidic chip, precision friction pair and other fields.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision micro-nano functional surface manufacturing technology, and in particular to a processing method and tool holder device for a sidewall nanograting-microgroove composite texture. Background Technology

[0002] Microgroove-nanograting cross-scale composite textures combine the fluid control and oil storage lubrication functions of micrometer-scale grooves with the optical diffraction and slip-reduction properties of nanometer-scale gratings, making them highly valuable for engineering applications in optical structural color elements, diffraction anti-counterfeiting devices, microfluidic chips, and precision motion pair functional surfaces. Current fabrication processes for micro / nano composite textures mainly include photolithography, femtosecond laser processing, and single-point diamond cutting. Among these, axial ultrasonic-assisted single-point diamond cutting has become the mainstream processing technology for micro / nano texture fabrication due to its advantages such as no heat-affected zone, wide material compatibility, and high processing efficiency.

[0003] Currently, research and applications in the fabrication of microgroove textures using ultrasonic-assisted diamond cutting generally employ a single-tool, single-pass machining method. Systematic and in-depth research on the forming mechanism and control methods for differentiated composite textures is still lacking. Existing processes cannot achieve differentiated texture control in different regions of the groove, making it difficult to simultaneously meet the dual performance requirements of functionalized nanogratings on the sidewalls and ultra-smooth groove bottoms. If multi-step machining or a dual-spindle scheme is used to achieve differentiated structures, problems such as large alignment errors during secondary clamping, high equipment costs, and poor consistency in batch processing arise. Furthermore, there are few technical solutions based on a single ultrasonic tool holder for the synergistic processing of vibration-based nanograting fabrication and vibration-free precision machining. Therefore, there is an urgent need to develop a machining method for sidewall nanograting-microgroove composite textures based on a single ultrasonic composite tool holder, providing technical support for the high-quality and efficient fabrication of functional micro / nano textured surfaces. Summary of the Invention

[0004] (a) Purpose of the invention

[0005] To address the shortcomings of existing technologies, this invention provides a processing method and tool holder device for sidewall nanograting-microgroove composite textures. It aims to solve the problems of existing ultrasonic-assisted single-point diamond cutting, which makes it difficult to control the microgroove texture in different areas, multi-process / dual-spindle processing with large errors and high costs, and the lack of single-tool holder technology for co-vibration / vibrationless preparation of nanogratings. This invention achieves high-quality and efficient forming of functional micro-nano composite surfaces.

[0006] (II) Technical Solution

[0007] The technical means employed in this invention are as follows:

[0008] A standing wave node adapter type composite machining tool holder, characterized in that it includes a front vibration machining unit and a rear follower machining unit; the front vibration machining unit consists of a front V-shaped machining tool, a rear end cover, an amplitude transformer, a front end cover, a piezoelectric ceramic assembly, and an electrode pad; the rear follower machining unit includes a rear V-shaped tool holder body, a standing wave node adapter plate, and a rear V-shaped machining tool.

[0009] Furthermore, during operation of the pre-vibration machining unit, a stable longitudinal standing wave is formed inside the amplitude transformer, and the section where the front end cover is located is the standing wave node region, with the axial vibration amplitude approximately zero. The pre-positioned V-shaped machining tool in the pre-vibration machining unit is fixedly installed at the output end of the amplitude transformer, generating high-frequency ultrasonic vibration.

[0010] Furthermore, one end of the standing wave node adapter plate of the rear follow-up machining unit is rigidly fixed to the standing wave node section of the amplitude transformer, and the other end is rigidly connected to the main body of the rear V-shaped tool holder; the rear V-shaped machining tool is fixedly clamped at the end of the main body of the rear V-shaped tool holder, and arranged in front and behind the front V-shaped machining tool along the feed direction; the tip of the rear V-shaped machining tool is lower than the tip of the front V-shaped machining tool, and the height difference between the two is the cutting depth of the groove bottom; since the installation position is the standing wave node, the rear V-shaped machining tool moves with the tool holder and has no high-frequency vibration, which is used to process the bottom of the groove and retain the side wall nano-grating.

[0011] Furthermore, the standing wave node adapter type composite machining tool holder is characterized in that the standing wave node is located at the front end cover section of the ultrasonic transducer or at the mounting flange section of the amplitude transformer; the standing wave node adapter plate is made of high-rigidity hard alloy material and is rigidly locked to the standing wave node section by bolts.

[0012] Furthermore, both the front and rear V-shaped machining tools of the standing wave node adapter composite machining tool holder are single-crystal diamond V-shaped tips; for different microgrooves and nanogratings, the cutting edge shape of the front and rear machining tools is any one of V-shaped tips, trapezoidal tools or circular arc drum-shaped tools, and the tool material is single-crystal diamond.

[0013] Furthermore, the height difference between the front V-shaped machining tool and the rear V-shaped machining tool in the standing wave node adapter composite machining tool holder is 0.3~1 µm. This height difference is the cutting depth of the rear V-shaped machining tool, which is greater than the height of the nano-grating peak and valley at the bottom of the groove generated by the front tool.

[0014] Furthermore, the standing wave node-type composite machining tool holder is also equipped with an ultrasonic drive and online monitoring unit, including a signal generator, a power amplifier, a laser vibrometer, and an ultrasonic vibration monitor connected in sequence. The sinusoidal excitation waveform output by the signal generator is amplified by the power amplifier and then connected to the ultrasonic transducer unit. The laser vibrometer collects the tool tip vibration signals of the front and rear tools and transmits them to the ultrasonic vibration monitor to realize closed-loop control of vibration parameters.

[0015] This invention also discloses a method for fabricating a sidewall nanograting-microgroove composite texture, comprising the following steps:

[0016] Step 1: Fix the workpiece to be processed on the processing platform; install the composite tool holder on the processing spindle, ensuring that the vibration direction is completely coaxial with the Z-axis.

[0017] Step 2: Complete the tool setting operation by moving the machining platform and the machining spindle; set the initial cutting depth of the front tool and the height difference between the rear V-shaped machining tool and the front V-shaped machining tool to ensure that the horizontal feed paths of the two tools are aligned.

[0018] Step 3: Turn on the signal generator and power amplifier, set the resonant frequency to 20~40 kHz and the amplitude to 1~5µm, and use a laser vibrometer to detect the vibration state of the two tools. Make the front tool output stable vibration and the rear tool in a near-zero vibration state. If the requirements are not met, fine-tune the excitation parameters.

[0019] Step 4: Set the cutting parameters such as feed rate, texture spacing, and grating spacing, and control the machining platform to feed at a constant speed along the X direction. The composite tool holder holds the tool and feeds synchronously. The front V-shaped machining tool first cuts the workpiece to create a continuous V-shaped groove, and at the same time generates a nano-grating on the side wall and the bottom of the groove. The rear V-shaped machining tool then cuts the groove and processes the nano-grating at the bottom of the groove with a preset cutting depth. After processing, the nano-grating on the side wall is retained. The composite texture is formed in a single pass.

[0020] Step 5: After machining a single groove, control the tool to lift up and continuously cut along the Y-axis at the set texture spacing. Repeat the single cutting process to complete the batch preparation of the groove array on the workpiece surface.

[0021] Step 6: Turn off the signal generator and power amplifier in sequence, remove the workpiece and inspect the machining morphology, groove bottom roughness, and optical / friction properties; if the effect is not satisfactory, readjust the parameters until the machining requirements are met.

[0022] Furthermore, in step four, the surface roughness Ra at the bottom of the trench after fine machining is ≤10 nm.

[0023] Furthermore, in step four, the spacing of the sidewall nanogratings satisfies the formula d=v / f, where d is the grating spacing, v is the X-axis feed velocity, and f is the vibration frequency; the grating spacing can be adjusted in the range of 400~900 nm.

[0024] Furthermore, the workpieces to be processed are not limited to aluminum alloys, titanium alloys, and mold steel; single-crystal SiC, quartz glass, and single-crystal silicon-based hard and brittle optical materials are also within the processing range.

[0025] (III) Beneficial Effects

[0026] By leveraging the zero-amplitude characteristics of ultrasonic standing wave nodes, differentiated vibration of dual tools on a single tool holder is achieved, eliminating the need for independent dual spindles and complex vibration isolation structures. Fine machining of the sidewall nanogratings and bottom grooves can be completed through a single-pass cutting process, eliminating secondary clamping and alignment errors. This significantly improves machining efficiency compared to multi-stage cutting processes and dramatically enhances batch processing consistency. The controllable sidewall nanogratings enable optical diffraction, structural color rendering, and slip friction reduction effects, while the ultra-smooth groove bottom ensures low-resistance fluid transport, optical reflection accuracy, and low wear characteristics. The integrated design of functional texture and high-precision surface is simultaneously achieved within a single groove. Only node conversion design is required for existing ultrasonic tool holders, and a precision machining platform is needed to achieve composite texture machining of metals and various hard and brittle optical materials. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating the fabrication method of the sidewall nanograting-microgroove composite texture provided by this invention;

[0029] Figure 2 A schematic diagram of the overall structure of the standing wave node adapter composite machining tool holder provided by the present invention;

[0030] Figure 3 A schematic diagram illustrating the processing principle of the sidewall nanograting-microgroove composite texture provided by the present invention;

[0031] Figure 4 A schematic diagram of the processing equipment for the sidewall nanograting-microgroove composite texture provided by the present invention;

[0032] Figure 5 The diagram shows three types of machining tools provided by the present invention, wherein (a) is a trapezoidal tool, (b) is a V-shaped tool, and (c) is a circular arc drum-shaped tool.

[0033] In the diagram: 1. Front-mounted V-shaped machining tool; 2. Amplitude transformer; 3. Front end cover; 4. Piezoelectric ceramic assembly; 5. Electrode pad; 6. Rear end cover; 7. Rear-mounted V-shaped machining tool; 8. Standing wave node adapter plate; 9. Rear-mounted V-shaped tool holder body; 10. Machining spindle; 11. Ultrasonic vibration monitor; 12. Laser vibrometer; 13. Composite tool holder; 14. Machining platform; 15. Machining workpiece; 16. Power amplifier; 17. Signal generator; Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, this invention discloses a method for fabricating a sidewall nanograting-microgroove composite texture, the method comprising the following steps:

[0036] Step 1: Fix the workpiece 15 on the machining platform 14; install the composite tool holder 13 on the lower end of the machining spindle 10, ensuring that the vibration direction is completely coaxial with the Z-axis.

[0037] Step 2: The tool setting operation on the surface of the workpiece 15 is completed by moving the machining platform 14 and the machining spindle 10; the initial cutting depth of the front V-shaped machining tool 1 is set, and the height difference H between the tip of the rear V-shaped machining tool 7 and the front V-shaped machining tool 1 is set to ensure that the horizontal feed trajectories of the two tools are the same.

[0038] Step 3: Turn on the signal generator 17 and power amplifier 16, set the resonant frequency to 20~40 kHz and the amplitude to 1~5 µm, and use the laser vibrometer 12 to detect the vibration state of the two tools. Display the amplitude on the ultrasonic vibration monitor 11. If the requirements for ultrasonic vibration of the front tool and no vibration of the rear tool are not met, return to re-optimize the parameters.

[0039] Step 4: Set the cutting parameters such as feed speed v, texture spacing C, and grating spacing d, and control the machining platform 14 to feed at a constant speed along the X direction. The composite tool holder 13 holds the tool and feeds synchronously. The front V-shaped machining tool 1 first cuts the workpiece 15 to create a continuous V-shaped groove, and at the same time generates a periodically controllable nano-grating on the side wall and the bottom of the groove. The rear V-shaped machining tool 7 then enters the groove and cuts the nano-grating at the bottom of the groove with a preset cutting depth, thereby retaining the nano-grating on the side wall. The composite texture is formed in a single pass.

[0040] Step 5: After machining a single groove, control the tool to lift up and repeat the single-pass cutting process along the Y-axis at the set texture spacing C to complete the batch preparation of the groove array on the workpiece surface.

[0041] Step 6: After the array processing is completed, turn off the signal generator 17 and the power amplifier 16 in sequence; use relevant equipment to test the processing morphology, roughness, and optical / friction properties; if the effect is not good, readjust the process parameters and reprocess until the processing requirements are met.

[0042] like Figure 2 As shown, the standing wave node adapter-type composite machining tool holder is composed of a front vibration machining unit and a rear follower machining unit. The front vibration machining unit consists of a front V-shaped machining tool 1, a rear end cover 6, an amplitude transformer 2, a front end cover 3, a piezoelectric ceramic assembly 4, and an electrode pad 5. During operation, a stable longitudinal standing wave is formed inside the amplitude transformer, and the section where the front end cover 3 is located is the standing wave node region, with an axial vibration amplitude approximately zero. The front V-shaped machining tool 1 in the front vibration machining unit is fixedly installed at the output end of the amplitude transformer 2 and undergoes high-frequency ultrasonic vibration along with the amplitude transformer. The rear follower machining unit includes a rear V-shaped tool holder body 9, a standing wave node adapter plate 8, and a rear V-shaped machining tool 7. One end of the standing wave node adapter plate 8 is rigidly locked to the standing wave node section of the front end cover 3, and the other end is fixedly connected to the rear V-shaped tool holder body 9. The rear V-shaped machining tool 7 is fixedly installed at the end of the rear V-shaped tool holder body 9 and is arranged in a front-to-back manner with the front V-shaped machining tool 1 along the feed direction.

[0043] like Figure 3As shown, in the initial stage, the workpiece 15 to be processed is clamped and fixed on the processing platform 14, with a flat surface, and the tool setting and parameter calibration are completed. In the processing stage, the front V-shaped tool 1 performs high-frequency intermittent cutting, first cutting into the workpiece 15 to create a V-shaped groove, and simultaneously generating uniform nano-gratings with a spacing length of L on the sidewall and bottom of the groove; the rear V-shaped tool 7 is fixed through the standing wave node adapter plate 8 of the standing wave node, without high-frequency vibration, and follows the front V-shaped tool 1 along the same trajectory to complete the processing of the nano-grating at the bottom of the groove with a preset cutting depth H, leaving only the sidewall nano-grating after processing. In the forming stage, after the processing of a single groove is completed, the single cutting process is repeated along the Y-axis with a certain texture spacing C, finally obtaining a large-area regular V-shaped micro-groove array, with controllable nano-gratings on the sidewalls of the groove and ultra-smooth, grating-free bottom.

[0044] like Figure 4 As shown, the ultrasonic drive monitoring unit consists of a signal generator 17, a power amplifier 16, an ultrasonic vibration monitor 11, and a laser vibrometer 12, which are connected in sequence. The signal generator 17 outputs a sinusoidal excitation waveform with a set frequency and amplitude. After being amplified by the power amplifier 16, the waveform is input to the piezoelectric ceramic component of the composite tool holder 13, which excites longitudinal axial vibration, driving the front V-shaped tool 1 to achieve high-frequency ultrasonic intermittent cutting. The laser vibrometer 12 collects the displacement signal of the tool tip vibration in a non-contact manner and transmits it to the ultrasonic vibration monitor 11 to complete the vibration parameter analysis and testing. The output parameters are dynamically corrected and closed-loop controlled to improve the stability of the machining process.

[0045] like Figure 5 As shown, to adapt to different microgrooves and nanograting shapes, different trapezoidal tools, V-shaped tools, and circular arc drum-shaped tools are selected. Each type of tool is provided with two specifications: large and small. Large-specification tools are used for the pre-grooving and nanograting preparation process, while small-specification tools are suitable for the post-groove bottom fine machining process.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A standing wave node adapter type composite machining tool holder, characterized in that, It includes a front vibration machining unit and a rear follow-up machining unit; the front vibration machining unit consists of a front V-shaped machining tool, a rear end cover, an amplitude transformer, a front end cover, a piezoelectric ceramic assembly, and an electrode pad; the rear follow-up machining unit includes a rear V-shaped tool holder body, a standing wave node adapter plate, and a rear V-shaped machining tool. During operation, the pre-vibration processing unit generates a stable longitudinal standing wave inside the amplitude transformer, with the front cover located at the standing wave node region, where the axial vibration amplitude is approximately zero. The pre-positioned V-shaped machining tool in the pre-vibration processing unit is fixedly installed at the output end of the amplitude transformer, generating high-frequency ultrasonic vibration. One end of the standing wave node adapter plate of the rear follow-up machining unit is rigidly fixed to the standing wave node section of the amplitude transformer, and the other end is rigidly connected to the main body of the rear V-shaped tool holder. The rear V-shaped machining tool is fixedly clamped at the end of the main body of the rear V-shaped tool holder and arranged in front and behind the front V-shaped machining tool along the feed direction. The tip of the rear V-shaped machining tool is lower than the tip of the front V-shaped machining tool, and the height difference between the two is the cutting depth of the groove bottom. Since the installation position is the standing wave node, the rear V-shaped machining tool moves with the tool holder and has no high-frequency vibration. It is used to process the bottom of the groove and retain the side wall nano-grating.

2. The standing wave node adapter type composite machining tool holder according to claim 1, characterized in that, The standing wave node is located at the front cover section of the ultrasonic transducer or at the mounting flange section of the amplitude transformer; the standing wave node adapter plate is made of high-rigidity hard alloy material and is rigidly locked to the standing wave node section by bolts.

3. The standing wave node adapter type composite machining tool holder according to claim 1, characterized in that, Both the pre-processing V-shaped tool and the post-processing V-shaped tool are single-crystal diamond V-shaped tips. For different microgrooves and nanograting fabrications, the cutting edge shape of the pre-processing tool and the post-processing tool can be any one of a V-shaped tip, a trapezoidal tool, or a circular arc drum-shaped tool, and the tool material is single-crystal diamond.

4. The standing wave node adapter type composite machining tool holder according to claim 1, characterized in that, The height difference between the front V-shaped machining tool and the rear V-shaped machining tool is 0.3~1 µm. This height difference is the cutting depth of the rear V-shaped machining tool, which is greater than the height of the peak and valley of the nano-grating at the bottom of the groove generated by the front tool.

5. The standing wave node adapter type composite machining tool holder according to claim 1, characterized in that, It is also equipped with an ultrasonic drive and online monitoring unit, including a signal generator, a power amplifier, a laser vibrometer, and an ultrasonic vibration monitor connected in sequence. The sinusoidal excitation waveform output by the signal generator is amplified by the power amplifier and then connected to the ultrasonic transducer unit. The laser vibrometer collects the blade tip vibration signals before and after the blade is moved and transmits them to the ultrasonic vibration monitor to realize closed-loop control of vibration parameters.

6. A method for fabricating a sidewall nanograting-microgroove composite texture, characterized in that, The method of using the standing wave node adapter-type composite machining tool holder according to any one of claims 1 to 5 includes the following steps: Step 1: Fix the workpiece to be processed on the processing platform; install the composite tool holder on the processing spindle, ensuring that the vibration direction is completely coaxial with the Z-axis. Step 2: Complete the tool setting operation by moving the machining platform and the machining spindle; set the initial cutting depth of the front tool and the height difference between the rear V-shaped machining tool and the front V-shaped machining tool to ensure that the horizontal feed paths of the two tools are aligned. Step 3: Turn on the signal generator and power amplifier, set the resonant frequency to 20~40 kHz and the amplitude to 1~5 µm, and use a laser vibrometer to detect the vibration state of the two tools. Make the front tool output stable vibration and the rear tool in a near-zero vibration state. If the requirements are not met, fine-tune the excitation parameters. Step 4: Set the cutting parameters such as feed rate, texture spacing, and grating spacing, and control the machining platform to feed at a constant speed along the X direction. The composite tool holder holds the tool and feeds synchronously. The front V-shaped machining tool first cuts the workpiece to create a continuous V-shaped groove, and at the same time generates a nano-grating on the side wall and the bottom of the groove. The rear V-shaped machining tool then cuts the groove and processes the nano-grating at the bottom of the groove with a preset cutting depth. After processing, the nano-grating on the side wall is retained. The composite texture is formed in a single pass. Step 5: After machining a single groove, control the tool to lift up and continuously cut along the Y-axis at the set texture spacing. Repeat the single cutting process to complete the batch preparation of the groove array on the workpiece surface. Step 6: Turn off the signal generator and power amplifier in sequence, remove the workpiece and inspect the machining morphology, groove bottom roughness, and optical / friction properties; if the effect is not satisfactory, readjust the parameters until the machining requirements are met.

7. The processing method and tool holder device for the sidewall nanograting-microgroove composite texture according to claim 6, characterized in that, In step four, the surface roughness Ra at the bottom of the trench after fine machining is ≤10 nm.

8. The fabrication method of the sidewall nanograting-microgroove composite texture according to claim 6, characterized in that, In step four, the spacing of the sidewall nanogratings satisfies the formula d=v / f, where d is the grating spacing, v is the X-axis feed velocity, and f is the vibration frequency; the grating spacing can be adjusted in the range of 400~900 nm.

9. The processing method of the sidewall nanograting-microgroove composite texture according to claim 6, characterized in that, The workpiece to be processed is an aluminum alloy, titanium alloy, mold steel or other metal materials, or a single crystal SiC, quartz glass or single crystal silicon or other hard and brittle optical materials.

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