Microtexture preparation device and method for inhibiting ablation defect of hard alloy through laser-ultrasonic combination

Abstract

The invention provides a micro-texture preparation device and method for inhibiting hard alloy ablation defects through laser-ultrasonic combination, and relates to the technical field of alloy ablation machining, and the micro-texture preparation device comprises an ultrasonic vibration coupling device used for assembling a hard alloy workpiece; the laser ablation device is used for scanning and ablating the surface of the hard alloy workpiece to form a microstructure; wherein the coupling clamp is used for rigidly clamping the hard alloy workpiece and enabling the hard alloy workpiece to be in rigid or coupling contact with the output end of the ultrasonic transducer; the nanosecond pulse laser outputs nanosecond pulse laser, and finally the laser beam is focused on the surface of the hard alloy workpiece through the focusing optical lens to form a light spot. According to the method, the defect inhibition effect is remarkable, splashing of a micro-texture area can be reduced, and micro-cracks caused by expansion of thermal stress along a grain boundary are basically eliminated; the geometric accuracy and the surface quality are greatly improved; and the method is high in process robustness and easy to implement, and has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of alloy ablation processing technology, specifically to a microtexture preparation device and method for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method. Background Technology

[0002] Carbide, due to its excellent high hardness, high wear resistance, and good high-temperature stability, has become a key material for manufacturing high-end cutting tools, precision molds, and wear-resistant parts. To improve the service performance of carbide tools under extreme friction conditions, fabricating micron-scale regular textures on its surface has become an effective surface modification method. These microtextures can trap wear debris, store lubricant, and alter surface contact states, thereby significantly improving tribological properties. Currently, nanosecond pulsed laser processing technology, due to its high precision, high efficiency, and non-contact characteristics, has become the mainstream method for fabricating such microtextures.

[0003] Meanwhile, prior art application number "CN02813241.6" describes a method for ablating holes in a rigid non-metallic substrate. It provides at least one laser assembly capable of generating a focused laser beam on an axis, wherein the focus is movable relative to the axis. The focus of the laser beam is positioned on at least one surface adjacent to the substrate. A first layer of the substrate is ablated using the laser beam. The focus is moved relative to an axis corresponding to the depth of the substrate, thereby enabling the ablation of successive layers of the substrate, creating a hole within the substrate.

[0004] However, the aforementioned device still has some obvious defects in use: 1. When laser ablation of WC-Co cemented carbide, the Co binder phase melts and vaporizes rapidly to form steam bubbles, and the surface adsorbed gas is entrained into the molten pool, which easily leads to porosity defects under extremely high cooling rates; 2. The significant difference in the thermal expansion coefficients of the WC-Co phases generates huge thermal stress under high temperature gradients, inducing microcracks to propagate along grain boundaries; 3. Marangoni convection and recoil pressure in the molten pool cause unstable melt flow, resulting in irregular geometric morphology.

[0005] However, the aforementioned devices mainly employ methods that optimize laser process parameters. This method is essentially a passive adaptation to energy input and is difficult to intervene in the complex heat transfer, mass transfer, and fluid dynamics processes inside the molten pool from a physical mechanism perspective. Its effect on suppressing defects has approached its limit. In recent years, researchers have attempted to introduce external auxiliary energy fields, such as thermal fields or magnetic fields, but these methods are difficult to implement and costly in high-melting-point materials such as cemented carbide, and their effect on suppressing key defects such as spatter and microcracks is limited.

[0006] Therefore, there is an urgent need in this field for an innovative method that can actively intervene in the dynamic process of the molten pool from a physical mechanism perspective, fundamentally suppress the generation of defects, and is easy to integrate and implement with controllable costs. Summary of the Invention

[0007] The purpose of this invention is to provide a microtexture fabrication device and method for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A laser-ultrasound composite microtexture fabrication device for suppressing ablation defects in cemented carbide, the device being used in the ablation fabrication of WC-Co cemented carbide, comprising: An ultrasonic vibration coupling device is used to assemble cemented carbide workpieces and couple ultrasonic vibration energy to the cemented carbide workpieces. A laser ablation device is used to scan and ablate the surface of the cemented carbide workpiece to form a microtexture. The ultrasonic vibration coupling device includes an ultrasonic transducer and a coupling clamp. The coupling clamp is used to rigidly clamp the cemented carbide workpiece and make it form a rigid or coupled contact with the output end of the ultrasonic transducer so as to synchronously transmit ultrasonic vibration to the cemented carbide workpiece. The laser ablation device includes a nanosecond pulse laser and a focusing optical lens. The nanosecond pulse laser outputs nanosecond pulse laser light, and the focusing optical lens ultimately focuses the laser beam onto the surface of the cemented carbide workpiece to form a spot. When the laser ablation device performs scanning ablation, the ultrasonic vibration coupling device is controlled to output modulated ultrasonic vibrations to utilize the ultrasonic-induced cavitation effect and acoustic flow effect to intervene in the dynamic process of the cemented carbide molten pool and suppress microcracks and spatter defects.

[0009] Preferably, the coupling fixture is used to provide preload clamping force to prevent the cemented carbide workpiece from loosening and the ultrasonic energy from attenuating during processing. The coupling fixture is fixedly installed on the ultrasonic transducer by fastening screws. The ultrasonic transducer is used to generate mechanical vibration and apply it to the cemented carbide workpiece, so that the cemented carbide workpiece is simultaneously in a state of high-frequency ultrasonic vibration during laser ablation. The ultrasonic transducer is fixedly installed on the transducer mounting base.

[0010] Preferably, the ultrasonic vibration coupling device further includes a power amplifier and a signal generator. The signal generator is used to generate an ultrasonic excitation signal with a set frequency and waveform, and outputs the signal to the power amplifier. The power amplifier is used to amplify the excitation signal and drive the ultrasonic transducer, thereby continuously outputting an ultrasonic amplitude that meets the processing requirements.

[0011] Preferably, the laser ablation device further includes a light-blocking mirror and a reflector. The light-blocking mirror and the reflector are disposed in the optical path between the nanosecond pulse laser and the focusing optical lens. The light-blocking mirror controls the on / off state of the laser optical path, and the reflector changes the laser propagation direction and completes the optical path deflection, so that the laser beam is transmitted to the processing area according to the device layout.

[0012] Preferably, a two-axis moving platform is fixedly installed at the bottom of the transducer mounting base for supporting and positioning the ultrasonic vibration coupling device. The two-axis moving platform is used to realize the precise positioning and trajectory movement of the cemented carbide workpiece in two dimensions, thereby completing the processing position arrangement and path planning of the micro-textured array.

[0013] Preferred options also include: A synchronous and coordinated control system is connected to the ultrasonic vibration coupling device and the laser ablation device. It is used to synchronously control and maintain the cemented carbide workpiece in a set ultrasonic vibration state throughout the entire laser scanning ablation process. The synchronous and coordinated control system also includes a synchronization interface for realizing synchronous modulation of ultrasonic vibration output and laser processing pulse.

[0014] Preferably, the ultrasonic driving unit is configured to output ultrasonic vibration with a frequency of 20 kHz and an amplitude of 10~15 μm; The laser processing pulse is modulated to have a wavelength of 1064nm, a pulse width of 100-250ns, an average power of 20-50W, a pulse frequency of 20kHz, a scanning speed of 300-700mm / s, and a focused spot diameter of 50μm.

[0015] A method for preparing microtextures to suppress ablation defects in cemented carbide using a laser-ultrasound composite technique, employing the aforementioned microtexture preparation apparatus for suppressing ablation defects in cemented carbide, includes the following steps: S1. Rigid clamping and coupling of the workpiece: The cemented carbide workpiece is rigidly clamped through the coupling fixture to ensure that the cemented carbide workpiece is in rigid contact with the output end of the ultrasonic transducer, so as to establish a stable ultrasonic vibration transmission path. S2. Ultrasonic preload and stabilization: The ultrasonic vibration coupling device is activated to enable the cemented carbide workpiece to obtain and maintain stable ultrasonic vibration with a set amplitude and frequency. The output frequency of the vibration is 20kHz and the amplitude is 10~15μm. S3. Laser-ultrasonic synchronous scanning ablation: During the continuous operation of the ultrasonic vibration coupling device, the laser ablation device is activated. The laser processing pulse is modulated to a wavelength of 1064nm, a pulse width of 100-250ns, an average power of 20-50W, a pulse frequency of 20kHz, a scanning speed of 300~700mm / s, and a focused spot diameter of 50μm. The laser beam is controlled to scan and ablate the surface of the cemented carbide workpiece along a preset path, simultaneously forming a microtexture morphology. S4. Sequential shutdown and post-processing: After scanning is completed, the laser ablation device is turned off first, and the ultrasonic vibration coupling device is turned off after the workpiece cools down. Then the processed cemented carbide workpiece is cleaned and inspected.

[0016] Compared with the prior art, the beneficial effects of the present invention are: Significant defect suppression effect: Compared with non-ultrasonic processing with the same laser parameters, the method of the present invention can reduce spatter in the microtextured region and basically eliminate microcracks caused by thermal stress propagation along grain boundaries; Significantly improved geometric accuracy and surface quality: The microtexture contour clarity prepared by this device and method is improved by about 20%-30%, the edge sharpness is improved, the bottom flatness is improved, and the surface roughness Ra value can be reduced from 1.2-2.0μm without ultrasonic assistance to 0.4-0.8μm, which greatly improves the quality of workpiece processing; The process is robust and easy to implement: This method directly couples ultrasound to the workpiece, avoiding the introduction of complex devices in the laser optical path. The system integration is simple, the parameters are highly controllable, and it is suitable for the stable preparation of complex-shaped microtextures. Ultrasonic assistance has minimal impact on laser processing efficiency and has a promising future for industrial applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the laser-ultrasonic composite processing system of the present invention; Figure 2 This is a schematic diagram of the ultrasonic vibration coupling device of the present invention; Figure 3 This is a simulation diagram of the internal flow field and cavitation behavior of the molten pool under ultrasonic action according to the present invention; Figure 4 SEM image of the surface with micro-pitted micro-texture without ultrasound assistance; Figure 5 This is a SEM image of the surface morphology of the micro-dimpled micro-textured structure using ultrasound assistance in this invention. Figure 6 SEM morphology of the microgroove ablation path without ultrasound assistance; Figure 7 This is a SEM image of the ablation path using ultrasound-assisted microgroove scanning, as described in this invention.

[0018] In the diagram: 1 Nanosecond pulsed laser, 2 Optical barrier, 3 Reflector, 4 Focusing optical lens, 5 Fastening screw, 6 Carbide workpiece, 7 Coupling fixture, 8 Ultrasonic transducer, 9 Transducer mounting base, 10 Two-axis moving platform, 11 Power amplifier, 12 Signal generator. Detailed Implementation

[0019] 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, and 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.

[0020] Please see Figures 1 to 7 The present invention provides a technical solution: A laser-ultrasound composite microtexture fabrication device for suppressing ablation defects in cemented carbide, the device being used in the ablation fabrication of WC-Co cemented carbide, comprising: Laser ablation device The laser ablation device is responsible for generating and guiding a high-energy-density nanosecond pulsed laser beam to selectively ablate the surface of the cemented carbide workpiece 6, thereby etching out a microtexture with a preset pattern. The device mainly includes the following core components: Nanosecond pulsed laser 1: As the energy source of the device, it is used to generate nanosecond-level pulsed lasers with stable wavelength and controllable pulse energy. The preferred wavelength is 1064nm, the pulse width is adjustable in the range of 100-250ns, and the average power output range covers 20 to 50W. The pulsed beam generated by the nanosecond pulsed laser 1 has a high peak power and can instantly vaporize or melt hard alloy materials.

[0021] Light-blocking mirror 2: Located in the laser optical path, its core function is to control the start and stop of the processing. By controlling the entry or exit of the light-blocking mirror 2 into the optical path, the laser beam can be quickly and safely blocked or connected, so as to achieve precise control of the processing and avoid misoperation.

[0022] Reflector 3: Installed at the position where the optical path needs to be turned, its main function is to change the propagation direction of the laser beam. By carefully arranging one or more reflectors 3, the horizontal or vertical beam output by the laser 1 can be flexibly turned and guided to the final focusing component to adapt to different equipment space layouts.

[0023] Focusing optical lens 4: It is a key optical element in the optical path. Its function is to focus the collimated or transmitted laser beam into a very small, highly concentrated focal point. The focusing optical lens 4 focuses the laser beam into a spot with a diameter of about 50 μm and applies it to the surface of the cemented carbide workpiece 6, thereby obtaining an energy density sufficient to ablate the material and realize fine processing at the micron scale.

[0024] Ultrasonic vibration coupling device The core function of the ultrasonic vibration coupling device is to efficiently and stably transfer high-frequency mechanical vibration energy to the cemented carbide workpiece 6 during laser processing. The device mainly includes vibration generation, energy transfer, and clamping and fixing parts: The coupling fixture 7 is the key mechanical interface connecting the cemented carbide workpiece 6 and the vibration system. Its primary function is to rigidly clamp the cemented carbide workpiece 6, providing sufficient preload clamping force to prevent the workpiece from loosening due to vibration or impact during processing. Secondly, its structural design ensures that the surface of the cemented carbide workpiece 6 to be processed has good parallelism and close contact with the contact end face of the fixture, thereby forming a low-loss vibration transmission path, transmitting ultrasonic vibration synchronously and efficiently to the entire workpiece, and avoiding severe attenuation of ultrasonic energy at the interface. The coupling fixture 7 is usually fixed to the output end of the ultrasonic transducer 8 by fastening screws 5.

[0025] Ultrasonic transducer 8: It is the core execution component of the vibration generator. Its function is to convert the input electrical energy into mechanical vibration energy of the same frequency. In this device, the ultrasonic transducer 8 generates high-frequency mechanical vibration under the action of the drive signal, and applies the vibration directly to the cemented carbide workpiece 6 through its output end and coupling fixture 7, so that the cemented carbide workpiece 6 is always in the preset ultrasonic vibration environment throughout the laser ablation process.

[0026] Transducer mounting base 9: Used to securely mount and support the ultrasonic transducer 8 and its associated coupling clamp 7 and hard alloy workpiece 6. Its rigid structure ensures the stability of the vibration system and directs the vibration energy mainly to the workpiece, reducing unnecessary transmission to the frame.

[0027] Power amplifier 11: Since the excitation signal generated by the signal generator 12 has relatively low power, it is insufficient to directly drive the ultrasonic transducer 8 to achieve the required amplitude. The function of the power amplifier 11 is to amplify the voltage and current of the excitation signal and provide sufficient electrical power to drive the transducer 8 to generate a mechanical vibration amplitude that meets the processing requirements.

[0028] Signal generator 12: As the control core of the ultrasonic vibration system, it is used to generate electrical signals with specific frequencies and waveforms. By setting the signal generator 12, the key parameters such as the frequency and waveform of the output ultrasonic vibration can be precisely controlled.

[0029] III. Motion and Cooperative Control Systems Two-axis moving platform 10: Fixedly installed at the bottom of transducer mounting base 9, used to support the entire ultrasonic vibration coupling device and cemented carbide workpiece 6. The two-axis moving platform 10 can move precisely in a two-dimensional plane, thereby realizing the precise alignment and positioning of cemented carbide workpiece 6 relative to the fixed laser focus position, and the scanning trajectory movement according to the preset micro-texture pattern to complete the processing of complex arrays.

[0030] Synchronous Coordination Control System: This control system is electrically connected to the laser ablation device and the ultrasonic vibration coupling device respectively. Its core function is to achieve time-series coordination between laser processing and ultrasonic vibration. It ensures that at the same time that the nanosecond pulse laser 1 emits each or each series of ablation pulses, the cemented carbide workpiece 6 is in a stable and continuous ultrasonic vibration state. The advanced synchronous coordination control system can also achieve precise modulation and locking of ultrasonic vibration output and laser pulse in time through its synchronization interface to further optimize energy coupling efficiency.

[0031] Working principle overview: During processing, the synchronous and coordinated control system first activates the ultrasonic vibration coupling device. The signal generator 12 generates a set signal, which is amplified by the power amplifier 11 and drives the ultrasonic transducer 8. The vibration is transmitted to the firmly clamped cemented carbide workpiece 6 through the coupling fixture 7, placing it in a stable high-frequency micro-amplitude vibration state. Subsequently, the control system triggers the nanosecond pulse laser 1 to emit light. The laser beam is guided by the light-blocking mirror 2 and the reflector 3, and focused by the focusing optical lens 4 onto the surface of the vibrating workpiece 6 for ablation. At the same time, the two-axis moving platform 10 moves the workpiece along a predetermined path. During this process, the ultrasonic vibration acting on the molten laser pool induces strong cavitation and acoustic flow effects. The cavitation effect can break bubbles and refine grains; the acoustic flow effect can homogenize the temperature and composition of the molten pool. The two work together to significantly suppress the generation of microcracks, pores, and metal spatter, thereby obtaining a high-quality microtexture with clear contours, a smooth surface, and very few defects on the WC-Co cemented carbide surface.

[0032] Example 1: Fabrication of a micro-pit array 1. Purpose An array of regularly arranged circular micro-pits was prepared on the surface of YG8 cemented carbide, and the effect of laser-ultrasonic composite processing on improving the morphology quality and internal defects of the pits was evaluated.

[0033] 2. Materials and Equipment Workpiece material: YG8 cemented carbide, dimensions: 16mm×16mm×6mm.

[0034] Surface pretreatment: The surface of the cemented carbide workpiece 6 to be processed is polished with diamond polishing paste to reduce its surface roughness to below 0.5μm, followed by cleaning and drying.

[0035] Machining system: Laser: IPG nanosecond pulsed fiber laser with a core wavelength of 1064nm.

[0036] Ultrasonic system: Custom-designed ultrasonic vibration device with a maximum output amplitude of 20μm.

[0037] Clamping and Motion: A dedicated workpiece fixture is used to rigidly connect the cemented carbide workpiece 6 to the output end of the coupling fixture 7; a two-axis moving platform 10 is used to control the precise scanning of the laser beam.

[0038] 3. Processing parameters and steps Workpiece clamping and ultrasonic preloading: The pretreated carbide workpiece 6 is firmly installed on the output end of the coupling fixture 7 to ensure that the contact surfaces are parallel in order to achieve efficient transmission of ultrasonic vibration energy. The ultrasonic vibration system is started and the vibration frequency is set to 20kHz and the amplitude to 10μm, so that the workpiece is in a stable ultrasonic vibration environment before processing.

[0039] Laser parameter settings: Set the processing parameters for the nanosecond pulsed laser: average power 30W, pulse width 150ns, pulse frequency 20kHz, scanning speed 500mm / s, and focused spot diameter 50μm.

[0040] Synchronous composite processing: Under the condition of continuous ultrasonic vibration, the nanosecond pulse laser 1 is activated, and the laser beam processes the workpiece surface according to the preset "surface scanning" path. The goal is to prepare micro-pits with a diameter of 50μm and a depth of 15μm. The center-to-center distance between the pits is 30μm. Throughout the processing, the ultrasonic vibration direction is perpendicular to the workpiece surface.

[0041] Post-processing: After the laser scanning is completed, first turn off the laser output and let the cemented carbide workpiece 6 cool naturally in the ultrasonic field for about 15 seconds. Then turn off the ultrasonic system and finally remove the processed cemented carbide workpiece 6.

[0042] Example 2: Fabrication of parallel microgrooves 1. Purpose A series of parallel microgrooves were fabricated on the same material to further verify the defect suppression and morphology improvement effect of the laser-ultrasound composite process on linear microtextures.

[0043] 2. Materials and Equipment Completely identical to Example 1, using the same YG8 cemented carbide workpiece and the same laser-ultrasonic composite machining system.

[0044] 3. Processing parameters and steps Workpiece clamping and ultrasonic preloading: The operation is the same as in Example 1, but the ultrasonic amplitude is set to 12μm.

[0045] Laser parameter settings: Adjust the laser parameters accordingly: average power 35W, pulse width 150ns, pulse frequency 20kHz, scanning speed 400 mm / s, spot diameter 50μm.

[0046] Synchronous composite processing: Under the condition of continuous ultrasonic vibration, the nanosecond pulse laser 1 is activated and a unidirectional scanning strategy is adopted to process a series of parallel microgrooves on the surface of the cemented carbide workpiece 6. The target groove size is: width 50μm, depth 15μm, and the spacing between adjacent grooves is 200μm.

[0047] Post-processing: Same as in Example 1, first turn off the nanosecond pulse laser 1, then turn off the ultrasonic wave after cooling, and then remove the processed cemented carbide workpiece 6.

[0048] Comparative Example To ensure a fair comparison, a comparative example was set up. Except for not turning on the ultrasonic vibration system, the workpiece material, surface pretreatment state, laser processing parameters, and microtexture pattern design used in the comparative example were completely consistent with those of Example 1 and Example 2. That is, the comparative example only used pure laser ablation processing.

[0049] Effect verification and analysis The samples of the examples and comparative examples were compared and analyzed using characterization techniques such as scanning electron microscopy. The results are as follows: Surface morphology quality: as per the instruction manual. Figure 5 Included with instruction manual Figure 7 As shown, the micro-pits prepared in Examples 1 and 2 have sharp edges and clear outlines, smooth and flat pit walls, and no obvious molten metal splashes or deposits were observed at or around the pit opening. No obvious micro-crack networks were also found at the bottom of the pits. The clarity of the prepared microtexture outline was improved by approximately 20%-30%, the edge sharpness was enhanced, the bottom flatness was improved, and the surface roughness Ra value was reduced from 1.2-2.0 μm without ultrasonic assistance to 0.4-0.8 μm. In comparison, the attached manual... Figure 4 Included with instruction manual Figure 6 The surface quality of the micro-pits processed in the middle is poor. There is an obvious recast layer of molten material at the edge, the regularity of the shape is reduced, and micro-cracks are visible on the pit wall and the bottom of the pit. In addition, obvious porosity defects were observed at the bottom of the pit.

[0050] Conclusion: The comparative results clearly demonstrate that the laser-ultrasonic composite machining method described in this invention can effectively suppress ablation defects such as spatter, microcracks, and porosity commonly encountered in pure laser machining of cemented carbide, significantly improving the geometric accuracy and surface integrity of the microtexture. This is mainly due to the synergistic optimization of the cavitation effect and acoustic flow effect introduced by ultrasound into the molten pool dynamics and solidification process. When ultrasound propagates in the molten Co binder phase, it generates a periodically changing sound pressure field. When the sound pressure amplitude exceeds the cavitation threshold of the liquid, it induces the violent generation, oscillation, and collapse of cavitation bubbles. This process generates extremely high transient... The localized pressure and intense shock waves effectively break up existing bubbles in the molten pool into smaller, dispersed bubbles, significantly increasing their specific surface area and accelerating their buoyancy. Experiments show that under suitable ultrasonic parameters, bubble buoyancy can be increased by 3-5 times. Mechanical breakage of primary dendrites and coarse particles in WC provides effective heterogeneous nucleation sites, significantly increasing the nucleation rate and achieving grain refinement. The cavitation effect also promotes solute redistribution, reduces microsegregation, destroys the oxide film on the molten pool surface, improves material exchange between the melt and the environment, and facilitates gas removal. Simultaneously, when ultrasound propagates in viscous melts, it generates steady-state fluid flow due to sound energy dissipation—the acoustic flow effect. This forced convection violently stirs the molten pool, making the temperature and solute concentration fields more uniform, significantly reducing the temperature gradient and the resulting thermal stress, fundamentally reducing the tendency for microcrack initiation, promoting uniform distribution of alloying elements, avoiding local segregation, and accelerating the transport of gas and inclusions to the molten pool surface, thus improving material purity. Improving the thermal conductivity between the molten pool and the solid matrix optimizes the solidification process and reduces solidification shrinkage defects. The introduction of an ultrasonic field also alters the solidification path of the molten pool, promotes the transformation of columnar crystals to equiaxed crystals, further refines the microstructure, and improves the overall performance of the material.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A microtexture fabrication device for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method, characterized in that: This device is used in the ablation preparation of WC-Co cemented carbides, including: An ultrasonic vibration coupling device is used to assemble cemented carbide workpieces and couple ultrasonic vibration energy to the cemented carbide workpieces. A laser ablation device is used to scan and ablate the surface of the cemented carbide workpiece to form a microtexture. The ultrasonic vibration coupling device includes an ultrasonic transducer and a coupling clamp. The coupling clamp is used to rigidly clamp the cemented carbide workpiece and make it form a rigid or coupled contact with the output end of the ultrasonic transducer so as to synchronously transmit ultrasonic vibration to the cemented carbide workpiece. The laser ablation device includes a nanosecond pulse laser and a focusing optical lens. The nanosecond pulse laser outputs nanosecond pulse laser light, and the focusing optical lens ultimately focuses the laser beam onto the surface of the cemented carbide workpiece to form a spot. When the laser ablation device performs scanning ablation, the ultrasonic vibration coupling device is controlled to output modulated ultrasonic vibrations to utilize the ultrasonic-induced cavitation effect and acoustic flow effect to intervene in the dynamic process of the cemented carbide molten pool and suppress microcracks and spatter defects.

2. The microtexture fabrication device for suppressing ablation defects in cemented carbide using laser-ultrasound composite technology according to claim 1, characterized in that: The coupling fixture is used to provide preload clamping force to prevent the cemented carbide workpiece from loosening and the ultrasonic energy from attenuating during processing. The coupling fixture is fixedly installed on the ultrasonic transducer by fastening screws. The ultrasonic transducer is used to generate mechanical vibration and apply it to the cemented carbide workpiece, so that the cemented carbide workpiece is simultaneously in a state of high-frequency ultrasonic vibration during laser ablation. The ultrasonic transducer is fixedly installed on the transducer mounting base.

3. The microtexture fabrication device for suppressing ablation defects in cemented carbide using laser-ultrasound composite technology according to claim 2, characterized in that: The ultrasonic vibration coupling device also includes a power amplifier and a signal generator. The signal generator is used to generate an ultrasonic excitation signal with a set frequency and waveform, and outputs the signal to the power amplifier. The power amplifier is used to amplify the excitation signal and drive the ultrasonic transducer, thereby continuously outputting an ultrasonic amplitude that meets the processing requirements.

4. The microtexture fabrication device for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method according to claim 1 or 3, characterized in that: The laser ablation device also includes a light-blocking mirror and a reflector. The light-blocking mirror and the reflector are arranged in the optical path between the nanosecond pulse laser and the focusing optical lens. The light-blocking mirror controls the on / off state of the laser optical path, and the reflector changes the direction of laser propagation and completes the optical path deflection, so that the laser beam is transmitted to the processing area according to the device layout.

5. The microtexture fabrication device for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method according to claim 4, characterized in that: The bottom of the transducer mounting base is fixedly equipped with a two-axis moving platform for supporting and positioning the ultrasonic vibration coupling device. The two-axis moving platform is used to realize the precise positioning and trajectory movement of the cemented carbide workpiece in two dimensions, thereby completing the processing position arrangement and path planning of the micro-textured array.

6. The microtexture fabrication device for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method according to claim 5, characterized in that, Also includes: A synchronous and coordinated control system is connected to the ultrasonic vibration coupling device and the laser ablation device. It is used to synchronously control and maintain the cemented carbide workpiece in a set ultrasonic vibration state throughout the entire laser scanning ablation process. The synchronous and coordinated control system also includes a synchronization interface for realizing synchronous modulation of ultrasonic vibration output and laser processing pulse.

7. The microtexture fabrication device for suppressing ablation defects in cemented carbide using a laser-ultrasound composite method according to claim 6, characterized in that: The ultrasonic drive unit is configured to output ultrasonic vibrations with a frequency of 20 kHz and an amplitude of 10~15 μm. The laser processing pulse is modulated to have a wavelength of 1064nm, a pulse width of 100-250ns, an average power of 20-50W, a pulse frequency of 20kHz, a scanning speed of 300-700mm / s, and a focused spot diameter of 50μm.

8. A method for preparing microtextures to suppress ablation defects in cemented carbide using a laser-ultrasound composite method, comprising the microtexture preparation apparatus for suppressing ablation defects in cemented carbide as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Rigid clamping and coupling of the workpiece: The cemented carbide workpiece is rigidly clamped through the coupling fixture to ensure that the cemented carbide workpiece is in rigid contact with the output end of the ultrasonic transducer, so as to establish a stable ultrasonic vibration transmission path. S2. Ultrasonic preload and stabilization: The ultrasonic vibration coupling device is activated to enable the cemented carbide workpiece to obtain and maintain stable ultrasonic vibration with a set amplitude and frequency. The output frequency of the vibration is 20kHz and the amplitude is 10~15μm. S3. Laser-ultrasonic synchronous scanning ablation: During the continuous operation of the ultrasonic vibration coupling device, the laser ablation device is activated. The laser processing pulse is modulated to a wavelength of 1064nm, a pulse width of 100-250ns, an average power of 20-50W, a pulse frequency of 20kHz, a scanning speed of 300~700mm / s, and a focused spot diameter of 50μm. The laser beam is controlled to scan and ablate the surface of the cemented carbide workpiece along a preset path, simultaneously forming a microtexture morphology. S4. Sequential shutdown and post-processing: After scanning is completed, the laser ablation device is turned off first, and the ultrasonic vibration coupling device is turned off after the workpiece cools down. Then the processed cemented carbide workpiece is cleaned and inspected.

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