Laser three-dimensional engraving machine suitable for superhard material processing

Abstract

The invention provides a laser three-dimensional engraving machine suitable for superhard material processing. The laser three-dimensional engraving machine comprises a laser head, a focusing lens group, an acousto-optic deflection device, a polyhedral wedge prism group, a galvanometer, a galvanometer deflection motor and a focusing lens, the laser head generates pulse laser; the focusing lens group is used for adjusting a focal plane where a focal point is located after the laser passes through a focusing lens, and etching different height layers of the material; the acousto-optic deflection device linearly deflects the laser and controls the laser to be emitted to different side reflecting surfaces of the wedge-shaped prism at different moments; the polyhedral wedge-shaped prism group is formed by sequentially arranging a plurality of wedge-shaped prisms according to spatial positions, and laser is reflected by the side surfaces of the wedge-shaped prisms to form line scanning; the galvanometer deflection motor drives the galvanometer to deflect the line laser formed after passing through the wedge-shaped prism group, and line scanning line feed is implemented; and the focusing lens focuses the laser deflected by the galvanometer into a focal plane. High-speed ablation of laser on the surface of the hard and brittle material is achieved, heat accumulation is reduced, and the machining precision and efficiency are improved.

Description

Technical Field

[0001] This invention belongs to the field of diamond-based composite material processing and relates to a laser three-dimensional engraving mechanism, which is particularly suitable for processing and heterogeneous molding of diamond-based composite materials such as diamond / silicon carbide, diamond / copper, and diamond / aluminum with a diamond volume fraction of more than 30%. Background Technology

[0002] Diamond-based composite materials, such as diamond / silicon carbide, have not yet been used in aerospace applications in my country. Abroad, regular flat diamond / silicon carbide composite materials with dimensions of 150mm have been developed for use as heat dissipation substrates in electronic devices. There are no publicly reported studies on the preparation and application of larger-sized materials, nor on their application in aerospace. Considering that existing materials generally have low thermal conductivity and high coefficients of thermal expansion, they cannot meet the high-precision imaging requirements of future next-generation cameras. Diamond / silicon carbide composite materials offer significant generational advantages in thermodynamic performance compared to existing materials. Therefore, both for urgent project needs and to promote technological advancement, there is an urgent need to develop large-size diamond / silicon carbide composite materials to achieve domestic substitution and engineering applications.

[0003] Abroad, diamond-based composite devices are widely used in high-energy lasers, large-scale integrated circuits, nuclear energy, and aerospace. Mechanical grinding is a common method for processing diamond-based composites, typically using grinding tools such as grinding wheels or abrasive discs to remove material through mechanical force and abrasive particles in contact with the surface of the diamond-based composite. However, the mechanical contact and anisotropic thermal diffusion during grinding inevitably cause damage such as amorphization, crystal dislocations, and lattice distortion, reducing the integrity of the processed surface and thus affecting the service performance of diamond-based composite devices. At the microscale fabrication level, ion etching is commonly used abroad for micro- and nano-fabrication of diamond-based composites, but the high processing cost and extremely low processing efficiency limit its widespread application. Laser processing technology has significant advantages such as high precision, controllability, speed, non-destructive processing, and no material limitations, and has attracted much attention in the field of special engineering material processing. Diamond / silicon carbide composites achieve densification and thermal expansion matching through the explosive evaporation of molten silicon, solid volume expansion, and heat release during the reaction process. Due to their unique thermal properties, the forming and processing of diamond / silicon carbide composites must take into account the mechanical and thermal coupling characteristics and differences between ultra-hard, high-thermal-conductivity diamond and low-density silicon carbide. This undoubtedly poses a severe challenge to precision forming and large-scale manufacturing. In recent years, with the development of laser processing technology and the expansion of material applications, especially the development of quantum technology, the precision processing of diamond and its composites has become a barrier to technological upgrading / leapfrog development in many industries.

[0004] In China, the ultra-high hardness and electrical insulation properties of diamond and its composite materials pose severe challenges to structural forming and processing. my country has explored various forming methods, including machining, waterjet machining, focused ion etching, reactive ion etching, and laser processing. Traditional machining methods suffer from high wear rates, high processing stress, and limited degrees of freedom. The ultra-hardness of materials restricts the efficiency of machining and waterjet machining, while the processing principle limits the efficiency of the currently dominant ion beam etching technology. Lasers, with their advantages of high peak power, fixed damage threshold, small heat-affected zone, high processing accuracy, and suitability for various difficult-to-machine ultra-hard materials, have become a focus of industry attention. High-quality laser processing of hard and brittle materials (such as glass, ceramics, silicon wafers, sapphire, and diamond) first requires effective control of the thermal effects and a quantitative ablation threshold. In particular, the rapid development of ultrafast optics and fiber lasers in recent years has led to a relatively systematic improvement and enhancement of laser processing technology in terms of laser output power, processing accuracy, and process parameters.

[0005] Lasers, with their advantages of high peak power, fixed damage threshold, small heat-affected zone, high processing accuracy, and suitability for various difficult-to-machine superhard materials, have become a focus of industry attention. High-quality laser processing of hard and brittle materials (such as glass, ceramics, silicon wafers, sapphire, and diamond) first requires effective control of the thermal effect and a quantitative ablation threshold. Limited by factors such as cost, long-pulse lasers in the microsecond and nanosecond range still dominate industrial processing. However, processing methods based on laser thermal removal mechanisms inevitably create a heat-affected zone, leading to problems such as frequent material recasting and surface delamination / cracking, posing a serious challenge in applications requiring micro / nano-scale precision processing. Currently, laser 3D engraving of diamond / silicon carbide composite surfaces mainly employs a dynamic collimating focusing galvanometer. In this system, the internal structure of the focusing galvanometer primarily consists of two XY digital galvanometer motors for transverse plane scanning ablation and one reciprocating motor for longitudinal focusing, which loads a beam expander. Due to the limited scanning speed of the digital galvanometer motors, the heat-affected zone formed during laser processing affects the final forming accuracy. The scanning speed of a digital galvanometer motor is negatively correlated with the laser power; that is, the higher the laser power, the slower the scanning speed. This results in slower processing speed, severe heat accumulation, low precision, and low efficiency when high-power lasers are used in the processing of hard and brittle materials. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, the inventors have conducted intensive research and provided a laser 3D engraving machine suitable for processing superhard materials. It adopts a combination of a multi-faceted wedge prism group and a galvanometer to significantly improve the laser scanning speed, achieve high-speed ablation of hard and brittle material surfaces by high-power laser, reduce the impact of heat accumulation, and improve processing accuracy and efficiency.

[0007] The technical solution provided by this invention is as follows: In the first aspect, a laser 3D engraving machine suitable for processing superhard materials includes: a laser head, a focusing lens group, an acousto-optic deflection device, a polyhedral wedge prism group, a galvanometer, a galvanometer deflection motor, and a focusing lens; the laser spindle optical path consists of the focusing lens group, the acousto-optic deflection device, the polyhedral wedge prism group, the galvanometer, and the focusing lens in sequence. The laser head generates pulsed laser light; The focusing lens group is used to adjust the focal plane where the laser focal point is located after passing through the focusing lens, so as to carry out etching of different height layers of material; The acousto-optic deflector linearly deflects the incident laser, controlling the laser to be directed toward the side reflective surfaces of different wedge prisms at different times. The polyhedral wedge prism assembly consists of multiple spatially arranged wedge prisms. The side of each wedge prism is a reflecting surface. The wedge prisms are driven by servo motors to rotate. The laser beam is reflected by the side of the wedge prisms to form a line scan. By adjusting the axial angle of the wedge prisms and the taper of the reflecting surface, the line trajectories of the reflected beams from each wedge prism can be made to appear as parallel or coincident scans on the focal plane of the focusing lens. The galvanometer deflection motor drives the galvanometer to deflect the line laser formed after passing through the wedge prism group, and performs line scanning line changing; when the acousto-optic deflection device linearly deflects the incident laser, the galvanometer deflection motor drives the galvanometer to deflect. The focusing lens focuses the laser light, after being deflected by the galvanometer, onto the focal plane.

[0008] Secondly, a method for processing superhard materials, using the aforementioned laser 3D engraving machine suitable for processing superhard materials, includes the following steps: Obtain a 3D model of the object to be sculpted, slice the 3D model into several layers, perform laser 2D planar scanning on each layer, and the layer height is less than the focal depth of the final focusing lens; The X-axis scanning in the two-dimensional plane is driven by a polyhedral wedge prism group, and the Y-axis scanning is driven by a galvanometer deflection motor. The pattern in this layer is binarized, and the binarization 0 and 1 correspond to laser off and laser on, respectively. The laser performs in-plane ablation and filling from left to right along the X direction and from top to bottom along the Y direction through a multi-faceted wedge prism group; after the ablation of the layer is completed, the focal point is moved down to the next layer by moving the distance between the plano-concave lens and the plano-convex lens in the focusing lens group. The carving process involves layer-by-layer ablation from top to bottom, ultimately achieving the overall carving.

[0009] The laser three-dimensional engraving machine for processing superhard materials provided by the present invention has the following beneficial effects: (1) The present invention provides a laser three-dimensional engraving machine suitable for processing superhard materials. In view of the problem that the current laser engraving equipment uses two XY digital galvanometer motors for transverse plane scanning and ablation and one reciprocating motor with a load beam expander for longitudinal focusing, the heat-affected zone formed by the laser during processing affects the final forming accuracy, the laser three-dimensional engraving machine of the present invention adopts a multi-faceted wedge prism group-array mirror and galvanometer and deflection motor method. By utilizing the high rotation speed of the wedge prism, the scanning speed is greatly improved, so that the high-power laser stays at each position of the target material for a very short time, reducing the dwell time of the laser point at each position, minimizing the accumulation of laser thermal effect, and improving forming accuracy; (2) The present invention provides a laser three-dimensional engraving machine suitable for processing superhard materials. In view of the problem of low laser utilization of a single wedge prism, multiple wedge prisms are selected, preferably two wedge prisms to form a wedge prism group. Combined with the laser deflection of the acousto-optic deflection device, the laser can be continuously etched on superhard materials such as diamond or diamond composite materials, thereby effectively improving the laser utilization. Attached Figure Description

[0010] Figure 1 A schematic diagram of a laser 3D engraving machine suitable for processing superhard materials; Figure 2 Schematic diagrams of wedge prisms with different tapers; Figure 3 A schematic diagram of an octagonal wedge prism; Figure 4 This is a schematic diagram of the optical path of the rotating mirror; Figure 5 Schematic diagram of focusing lens group Figure 6 The images are schematic diagrams of a cylindrical solid. The left image shows the overall view, and the right image shows a slice view. Figure 7 This is a schematic diagram of the laser beam trajectory. Figure 8 The engraving process for a small sample of diamond / silicon carbide composite material. Detailed Implementation

[0011] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0012] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0013] This invention provides a laser 3D engraving machine suitable for processing superhard materials, such as... Figure 1As shown, it includes a laser head, a focusing lens group, an acousto-optic deflection device, a polyhedral wedge prism group, a galvanometer, a galvanometer deflection motor, and a focusing lens. The laser main axis optical path consists of the focusing lens group, the acousto-optic deflection device, the polyhedral wedge prism group, the galvanometer, and the focusing lens.

[0014] The laser head is used to generate pulsed lasers, such as a 500W MOPA pulsed laser, which has a peak power of up to 50kW and emits pulsed lasers in the 1064nm band.

[0015] The focusing lens assembly consists of a single plano-concave lens and a single plano-convex lens. By shortening or increasing the distance between the plano-concave and plano-convex lenses, the laser divergence angle is expanded or contracted, causing the negative or positive defocus of the laser beam after passing through the focusing lens to change, thus achieving laser etching of different height layers of the material. Preferably, the plano-concave lens is fixed in the focusing lens assembly, and the plano-convex lens is loaded on a one-dimensional lead screw module platform to adjust the distance between the two lenses.

[0016] In one embodiment, such as Figure 5 As shown, the focusing lens group consists of a plano-concave lens with a diameter of 18.5mm and a focal length of F=-80mm, and a plano-convex lens with a diameter of 18.5mm and a focal length of F=100mm. The lens spacing between the two lenses is controlled to be 10~25mm. As the laser passes through the two lenses, the positional distance changes, ultimately achieving a linear change in focal length from -40mm to 40mm on the focal plane of the F254 quartz lens. In the focusing lens group, the plano-concave lens is fixed, and the plano-convex lens is loaded on a miniature one-dimensional slider module platform with a stroke of 20mm. The slider can be driven by a lead screw, a piezoelectric displacement motor, or a linkage mechanism connected to a galvanometer motor.

[0017] The acousto-optic deflector consists of an acousto-optic crystal, a piezoelectric ceramic wafer, and an RF driving module. Piezoelectric ceramic wafers are attached to both ends of the acousto-optic crystal. The RF driving module outputs a high-frequency driving voltage to the piezoelectric ceramic wafers, causing high-frequency resonance and generating mechanical waves that form a grating structure with varying density within the acousto-optic crystal. When the incident laser satisfies the Bragg diffraction angle, the incident laser is linearly deflected by adjusting the RF signal input to the RF driving module, controlling the laser to be directed towards different reflective surfaces of the wedge prism at different times.

[0018] In one embodiment, the acousto-optic crystal uses an ATOF acousto-optic deflector manufactured by Gooch, which controls the passing laser to deflect on a mrad scale by inputting a 0-10V analog signal.

[0019] A polyhedral wedge prism assembly consists of several wedge prisms arranged sequentially in spatial order. Each wedge prism's side is coated with a laser-reflective film or has a reflective mirror attached to form a reflective surface for reflecting laser light. The wedge prisms are driven to rotate by a high-speed servo motor, and the laser light, after being reflected by the sides of the wedge prisms, forms a line scan. The angle between the reflecting surface of the wedge prism's side and the base of the wedge prism is 30° to 90°. When the angle is 90°, the wedge prism functions as a conventional polyhedral prism. Figure 2 The front view shows wedge prisms with side mirrors at angles of 30°, 60°, and 90° to the bottom surface.

[0020] The laser beam is reflected at different angles by different wedge prisms. By selecting wedge prisms of the same or different types, the direction of the motor's main axis for each wedge prism is designed so that the laser beam, after passing through different wedge prisms at different times, remains on the focal plane of the focusing lens, with the line scanning directions parallel or overlapping. The laser beam forms a line laser after passing through the wedge prism group, and then the galvanometer deflection motor drives the galvanometer to deflect, achieving the line scanning line-changing operation and thus a surface-filling effect.

[0021] The biggest drawback of conventional multi-faceted rotating mirrors as laser scanning components is their low laser utilization rate, for the following reasons: An octagonal prism (or other prisms such as hexagonal or quadrangular prisms) consists of an octagonal prism with a reflector on each of its eight sides. A laser beam is incident at a specific angle onto each of the side reflectors, maintaining its direction while the prism rotates around its center. As the laser beam passes over the reflector, the angle of incidence relative to the reflector changes, resulting in a scan. For an octagonal prism, the laser beam must be turned off when it reaches the edge between adjacent side reflectors. It should only be turned back on after the beam has fully entered the reflector; otherwise, the edges of the reflectors will be damaged, eventually damaging the entire prism. The laser beam has a specific size. The angle A relative to the center of the octagonal prism is the actual output angle of the reflector. A full rotation results in an output angle of 8*A. This is considered in relation to laser utilization. β =N*A / 360, where N is the number of multi-faceted mirrors, and here N=8. For example... Figure 3 As shown, when the size of the side mirror of the prism is 20*18mm, the utilization rate of the prism when the laser travels from P1 to P2 is... β =8*28.72 / 360=63.8%, 100W pulse octagonal rotating mirror cleaning is equivalent to 63.8W pulse galvanometer cleaning efficiency, and the utilization rate of high-power pulsed laser prism will be even lower.

[0022] To avoid the problem of low utilization rate of a single wedge prism, which leads to a serious decrease in laser processing efficiency, this invention utilizes multiple multi-wedge prisms stacked in spatial order. By controlling the instantaneous deflection switching characteristics of an acousto-optic crystal, the laser is directed towards different wedge prism side mirrors at different times, thereby improving the utilization rate of the wedge prisms.

[0023] like Figure 4 As shown, when the polyhedral wedge prism assembly consists of a first wedge prism and a second wedge prism, after the laser beam is deflected once by the acousto-optic deflector, the refracted beam 1 is directed towards the first wedge prism. The rotation of the first wedge prism causes the reflected beam to scan back and forth, with the scanning range between beam 11 and beam 12. After a second deflection by the acousto-optic deflector, the refracted beam 2 is directed towards the second wedge prism. The rotation of the second wedge prism causes the reflected beam to scan back and forth, with the scanning range between beam 21 and beam 22. The angle between the main axes of the motors of the first and second wedge prisms is modulated. α The tapered slope of the wedge prism itself ensures that the linear trajectories between beams 11 and 12, and between beams 21 and 22, achieve parallel or overlapping scanning on the focal plane after focusing by the focusing lens. The two wedge prisms switch operation via an acousto-optic deflection device, achieving a near 100% theoretical laser utilization rate.

[0024] The working principle of the entire 3D forming process device is as follows: A 3D model of the object to be sculpted is acquired, sliced ​​into several layers, and each layer is subjected to laser 2D planar scanning. The layer height is less than the focal depth of the final focusing lens. The X-axis scanning in the 2D plane is driven by a polyhedral wedge prism group, and the Y-axis scanning is driven by a galvanometer deflection motor. The pattern within each layer is binarized, with 0 and 1 corresponding to laser off and on, respectively. The laser ablates and fills the plane from left to right along the X-axis and from top to bottom along the Y-axis through the polyhedral wedge prism group. After the layer is ablated, the focal point is moved to the next layer by adjusting the distance between the plano-concave and plano-convex lenses within the focusing lens group. This layer-by-layer ablation and carving is performed from top to bottom, ultimately achieving the overall sculpting.

[0025] To avoid the problem of low utilization rate of single rotating mirror scanning, which leads to a serious decrease in laser processing efficiency, this invention utilizes multiple multi-wedge prisms stacked together. By controlling the instantaneous deflection switching characteristics of the acousto-optic crystal, the laser passes through different multi-prism side scanning mirrors at different times, thereby improving the utilization rate of the rotating mirror.

[0026] Example A 500W MOPA pulsed laser is used, with a peak power of up to 50kW, emitting pulsed laser light in the 1064nm band. The acousto-optic crystal is an ATOF acousto-optic deflector device manufactured by Gooch. This acousto-optic deflector device controls the deflection of the laser light on a mrad scale by inputting a 0~10V analog signal. The polyhedral wedge prism group contains two polyhedral prisms with a 90° inclination angle between the side and the bottom surface, and has 10 faces. The sides of the prisms are coated with a metal film in the 1064nm reflection band. The prisms are rotated by a servo motor with a maximum speed of 6500r / min. The galvanometer is a 20-spot deflection galvanometer manufactured by CTI Corporation, with a maximum speed of 6m / s.

[0027] like Figure 5 As shown, the focusing lens group consists of a plano-concave lens with a diameter of 18.5mm and a focal length of F=-80mm, and a plano-convex lens with a diameter of 18.5mm and a focal length of F=100mm. The lens spacing between the two lenses is controlled to be 10~25mm. As the laser passes through the two lenses, the position and distance change, ultimately achieving a linear change in focal length from -40mm to 40mm on the focal plane of the F254 quartz lens. In the focusing lens group, the plano-concave lens is fixed, and the plano-convex lens is loaded on a miniature one-dimensional slider module platform with a stroke of 20mm. The slider can be driven by a lead screw, a piezoelectric displacement motor, or a linkage mechanism connected to a galvanometer motor.

[0028] The polyhedral wedge prism assembly is driven by a servo motor with a rotation speed set to 6000 r / min (100 r / s). The wedge prism has 10 faces. The servo motor driver outputs the current rotation angle, generating 100,000 pulses per revolution, meaning 10,000 pulses are output for each face rotation. The angle between the main axes of the two wedge prisms is adjusted so that they scan two adjacent parallel lines on the focal plane of the focusing lens, with a 50% overlap of the laser spots on the upper and lower lines.

[0029] like Figure 6 As shown, a cylindrical solid with a surrounding groove needs to be carved to a depth of 10mm. The model is then divided into sections. According to laser process experiments, when the laser is ablated at a power of 300W, the surface of the target material is removed to a depth of 50μm per ablation pass. Therefore, the number of sections is 200, and the height of each section is 50μm.

[0030] For each surface filling area within the layer, such as Figure 7As shown, the black area is the light-blocking area, and the white area is the light-emitting area. The laser scans from left to right and from top to bottom according to the current two-dimensional plane. The horizontal scanning trajectory from left to right along the X direction is controlled and driven by a polyhedral wedge prism group, and the horizontal scanning trajectory from top to bottom along the Y direction is controlled and driven by a high-speed galvanometer motor. The laser is deflected once by an acousto-optic deflector and directed towards the first wedge prism. The first row of the image is driven by face 1 of the first wedge prism. Within this row, the specific position of the laser point is obtained through the encoder signal fed back from the servo motor of the first wedge prism. When the laser point corresponds to the starting point area of ​​the first row of the image, the laser is enabled; when the laser point corresponds to the ending point area of ​​the first row of the image, the laser is disabled, no laser is emitted, and the scanning of that row of the image ends.

[0031] The laser is focused on the focal plane area of ​​the focusing lens to form the first row of ablation areas. The galvanometer motor deflects once, driving the laser focus to move to the second row of ablation positions.

[0032] The acousto-optic deflector deflects the laser beam a second time, directing it toward the second wedge prism. The second row of the image is driven by surface 1 of the second wedge prism. Within this row, the specific position of the laser point is obtained from the encoder signal fed back from the servo motor of the second wedge prism. When the laser point corresponds to the starting point area of ​​the second row of the image, the laser is enabled; when the laser point corresponds to the ending point area of ​​the second row of the image, the laser is disabled, no laser is emitted, and the scanning of that row of the image ends.

[0033] The laser is focused within the focal plane region of the focusing lens, forming the second row of ablation areas. The galvanometer motor deflects the laser once, driving the laser focus to move to the third row of ablation positions. The acousto-optic crystal deflects the laser towards the first wedge prism. Accordingly, the two faces of the first and second wedge prisms scan alternately, with the galvanometer motor deflecting the prisms during the scan.

[0034] Once the current layer 1 plane is scanned, the plano-convex lens of the focusing lens group moves forward by 266 μm, and the laser focus shifts downward by 50 μm. Based on this strategy, 200 layers of scanning ablation are completed.

[0035] Figure 8 The engraving process of a diamond / silicon carbide composite sample is shown.

[0036] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0037] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A laser 3D engraving machine suitable for processing superhard materials, characterized in that, include: Laser head, focusing lens group, acousto-optic deflection device, polyhedral wedge prism group, galvanometer, galvanometer deflection motor and focusing lens; The laser head generates pulsed laser light; The focusing lens group is used to adjust the focal plane where the laser focal point is located after passing through the focusing lens, so as to carry out etching of different height layers of material; The acousto-optic deflector linearly deflects the incident laser, controlling the laser to be directed toward the side reflective surfaces of different wedge prisms at different times. The polyhedral wedge prism assembly consists of multiple spatially arranged wedge prisms. The side of each wedge prism is a reflecting surface. The wedge prisms are driven by servo motors to rotate. The laser beam is reflected by the side of the wedge prisms to form a line scan. By adjusting the axial angle of the wedge prisms and the taper of the reflecting surface, the line trajectories of the reflected beams from each wedge prism can be made to appear as parallel or coincident scans on the focal plane of the focusing lens. The galvanometer deflection motor drives the galvanometer to deflect the line laser formed after passing through the wedge prism group, and performs line scanning line changing; when the acousto-optic deflection device linearly deflects the incident laser, the galvanometer deflection motor drives the galvanometer to deflect. The focusing lens focuses the laser light, after being deflected by the galvanometer, onto the focal plane.

2. The laser three-dimensional engraving machine for processing superhard materials according to claim 1, characterized in that, The power of the laser head is ≥500W.

3. The laser three-dimensional engraving machine for processing superhard materials according to claim 2, characterized in that, The focusing lens group consists of a single plano-concave lens and a single plano-convex lens. By adjusting the distance between the plano-concave lens and the plano-convex lens, the focal plane where the laser point is located after passing through the focusing lens is changed.

4. The laser three-dimensional engraving machine for processing superhard materials according to claim 1, characterized in that, The acousto-optic deflection device includes an acousto-optic crystal, a piezoelectric ceramic wafer, and a radio frequency (RF) driving module. The piezoelectric ceramic wafer is attached to both ends of the acousto-optic crystal. The RF driving module outputs a high-frequency driving voltage to the piezoelectric ceramic wafer. The mechanical wave generated by the high-frequency resonance of the piezoelectric ceramic wafer forms a sparse-dense grating structure inside the acousto-optic crystal. When the incident laser satisfies the Bragg diffraction angle, the incident laser is linearly deflected by adjusting the RF signal input to the RF driving module, controlling the laser to be directed toward different wedge-shaped prism side reflectors at different times.

5. The laser three-dimensional engraving machine for processing superhard materials according to claim 1, characterized in that, The angle between the reflecting surface on the side of the wedge prism and the bottom surface of the wedge prism is 30° to 90°.

6. The laser three-dimensional engraving machine for processing superhard materials according to claim 1, characterized in that, The polyhedral wedge prism assembly consists of two spatially arranged wedge prisms with a rotational speed ≥3000 r / min.

7. A method for processing superhard materials, using a laser three-dimensional engraving machine suitable for processing superhard materials as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Obtain a 3D model of the object to be sculpted, slice the 3D model into several layers, perform laser 2D planar scanning on each layer, and the layer height is less than the focal depth of the final focusing lens; The X-axis scanning in the two-dimensional plane is driven by a polyhedral wedge prism group, and the Y-axis scanning is driven by a galvanometer deflection motor. The pattern in this layer is binarized, and the binarization 0 and 1 correspond to laser off and laser on, respectively. The laser performs in-plane ablation and filling from left to right along the X direction and from top to bottom along the Y direction through a multi-faceted wedge prism group; after the ablation of the layer is completed, the focal point is moved down to the next layer by moving the distance between the plano-concave lens and the plano-convex lens in the focusing lens group. The carving process involves layer-by-layer ablation from top to bottom, ultimately achieving the overall carving.

Images