A laser compound processing method and system for a monolithic superhard cutter

Abstract

The application discloses a kind of laser composite processing method and system of monolithic superhard cutter, belong to cutter laser processing technical field, to the blank of monolithic superhard cutter is sequentially executed following steps: by laser beam, the outer contour of blank is turned and is obtained cutter shape foundation;According to the cross-sectional parameters of groove type, laser beam spot pattern is generated, laser beam is deflected by galvanometer system, makes laser beam fill in spot pattern, forms light cutter model, and simultaneously cooperates the multi-axis fitting motion of machine tool, completes the milling of cutter groove type;By laser beam, according to the cutting of blade structure on cutter;By galvanometer system control laser beam, keep machine tool unmoved, according to the micro-blade structure on cutter, engraving is processed.Integrates laser turning, milling and cutting, engraving, and different scales of cutter features are processed using differentiated processing strategies, which realizes the full-process integrated manufacturing of cutter finishing.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology for integral superhard cutting tools, and specifically relates to a laser composite processing method and system for integral superhard cutting tools. Background Technology

[0002] With the widespread application of composite materials and high-hardness metals, which are difficult to machine, in high-end manufacturing fields such as new energy vehicles and 3C electronics, higher demands are being placed on the performance of cutting tools. Superhard materials, represented by polycrystalline diamond (PCD) and chemical vapor deposition (CVD) diamond, have become ideal choices for manufacturing high-performance cutting tools due to their extremely high hardness, excellent wear resistance, and thermal conductivity. High-performance diamond tools, such as integral micro-cutting tools, drills, and end mills, designed and manufactured based on these materials, are gradually being introduced into the field of special materials machining.

[0003] In recent years, laser processing technology has been gradually applied to the machining of superhard material cutting tools due to its advantages such as non-contact operation, high precision, and wide material applicability. Currently, in the machining of welded PCD (polycarbide die) tools, laser cutting is mainly used. CAM software is used to describe the cutting edge shape, and the PCD composite sheet welded to a cemented carbide substrate is cut layer by layer to form the cutting edge and flank face of the tool. However, this machining method is mainly suitable for relatively simple cutting edges and flank faces, and it is difficult to meet the manufacturing requirements of integral cutting tools with complex three-dimensional structures and micro-cutting features.

[0004] As the complexity of the objects being processed increases, the application of monolithic superhard cutting tools is becoming increasingly widespread. These tools are typically machined from a single cylindrical material, possessing more complex geometric features. Using only a single laser cutting process, or simply following the machining methods of welded blade tools, or frequently changing machining equipment and clamping multiple times depending on the machining process, results in large tooling allowances and makes it impossible to simultaneously achieve efficient forming and precision machining.

[0005] Therefore, how to provide a laser composite machining method that can adapt to the multi-scale feature machining requirements of integral superhard tools and take into account both machining efficiency and accuracy is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] This invention provides a laser composite machining method and system for integral superhard cutting tools, realizing integrated manufacturing of the entire process from rough machining of the blank outer contour to complex groove forming, cutting edge structure finishing and micro-edge structure engraving. It solves the technical problems caused by the inability of existing single laser processing technology to simultaneously meet the multi-scale feature manufacturing requirements of efficient forming of integral tool outer contour, precise manufacturing of complex three-dimensional groove, precision machining of cutting edge structure and micro-edge structure engraving, as well as the cumbersome processing flow, the need for multiple sequence clamping, and the difficulty in balancing processing efficiency and accuracy.

[0007] The technical solution adopted in this invention is as follows: A laser composite machining method for integral superhard cutting tools involves sequentially performing the following steps on the blank of the integral superhard cutting tool: Control the movement of the laser beam and / or control the movement of the machine tool to perform turning machining on the outer contour of the blank through the laser beam to obtain a preset tool shape basis; Based on the cross-sectional parameters of the groove on the cutting tool, a laser beam spot pattern matching the shape of the groove cross-section is generated. The laser beam is deflected by a galvanometer system so that the laser beam fills the spot pattern. Based on the spatial parameters of the groove, it is mapped onto the spot pattern to form a light-cutting model matching the shape of the groove cross-section. Based on the light-cutting model and in conjunction with the multi-axis fitting motion of the machine tool, the milling of the cutting tool groove is completed. A laser beam is used to perform cutting based on the cutting edge structure of the tool; the cutting edge structure includes the tool tip, the cutting edge, and the flank face. The laser beam is controlled by a galvanometer system to keep the machine tool stationary. Based on the micro-edge structure on the cutting edge, a layered removal method is used for engraving.

[0008] The laser composite machining method using integral superhard cutting tools employed in this invention also has the following additional technical features: When machining the outer contour of the blank, a layered step-by-step machining process is adopted, including: The number of turning layers is determined based on the radius of the blank and the target machining radius of the tool; Based on the number of turning layers, select the incident position of the laser beam relative to the workpiece, and / or, Determine the number of repeated turning operations for each layer, and / or, Match laser parameters.

[0009] The number of turning layers is determined based on the radius of the blank and the target machining radius of the tool, specifically as follows: Based on the radius of the blank and the target machining radius of the tool, combined with the turning layer thickness, the number of turning layers is determined. From the outside in, as the number of machining layers increases, the thickness of the machining layer decreases.

[0010] Based on the number of turning layers, the incident position of the laser beam relative to the workpiece is selected, specifically as follows: At least the outermost turning layer is cut using half-tangential incident cutting or perpendicular irradiation cutting. At least the innermost turning layer uses tangential incident cutting. From the outside in, the incident position changes from semi-tangential incident cutting or perpendicular irradiation cutting to tangential incident cutting. The change of incident position is achieved by moving the blank relative to the laser beam along the radial direction of the blank, and / or, This is achieved by moving the laser beam relative to the blank along the radial direction of the blank.

[0011] Based on the number of turning layers, determine the number of repeated turning operations for each layer and match the laser parameters, specifically as follows: The outermost machining layer should be machined at least once. From the outside in, as the number of machining layers increases, the number of repeated machining operations also increases. From the outside in, the laser energy decreases as the number of machining layers increases.

[0012] Based on the aforementioned laser cutter model and simultaneously in conjunction with the multi-axis fitting motion of the machine tool, the specific steps are as follows: Based on the basic shape of the cutting tool and the cross-section of the cutting tool, the area to be removed that matches the groove shape is determined, and the spot pattern is obtained; Based on the groove width, helix angle, and groove depth, the laser pattern is mapped to generate a laser cutting tool model. Based on the model parameters of the laser cutting tool model, the multi-axis fitting motion of the machine tool is adjusted to perform laser milling of the groove.

[0013] Cutting is performed using a laser beam, based on the cutting edge structure of the tool. Specifically: Based on the cutting edge structure of the tool and combined with laser processing capabilities, the cutting width and depth of cut for each step are defined. The incident direction of the laser beam is controlled from the outside to the inside, and from the direction perpendicular to the axis of the tool to the direction inclined towards the cutting edge of the cutting edge structure, so as to perform layer-by-layer cutting.

[0014] Define the cut width and depth of cut for each step as follows: From the outside in, as the number of cutting layers increases, the cutting width and cutting depth decrease.

[0015] Carving and engraving processes include: In adjacent engraving layers, the laser beam engraving scans in different directions; The direction of the laser beam engraving scan includes at least one of 0°, 45°, 90°, and 135°.

[0016] The second aspect of this invention employs a laser composite machining system with an integral superhard tool for implementing the method, comprising: Five-axis motion machine tools are used to drive workpieces to achieve multi-axis linkage motion; A galvanometer system, including a laser, a mirror, a beam expander, a galvanometer, and a focusing mirror, is used to generate and control a laser beam; The control system is used to coordinate and control the motion trajectory of the five-axis machine tool and the laser deflection of the galvanometer system to achieve the switching and processing of turning, milling, cutting and engraving.

[0017] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are as follows: 1. In this invention, considering the structural characteristics of integral superhard cutting tools, four processing modes—laser turning, laser milling, laser cutting, and laser engraving—are sequentially executed on the same equipment, following a progressive processing logic based on decreasing dimensions. Laser turning is used to quickly remove blank allowance and shape the tool's outer contour; laser milling is used to process groove structures with complex three-dimensional geometric features; laser cutting is used for precision cutting of the cutting edge, cutting edge, and flank face; and laser engraving is used to process micro-edge structures. This multi-scale, hierarchical processing strategy effectively solves the technical challenge of existing single-laser processes simultaneously achieving efficient shaping of the integral tool's outer contour, precise manufacturing of complex three-dimensional grooves, and precision machining of cutting edge and micro-edge structures.

[0018] In the laser milling process, the laser beam filling trajectory is obtained based on the groove characteristics on the cutting tool. A galvanometer system deflects the laser beam to form a light-cutting model that matches the groove's cross-sectional shape. The machine tool is then controlled to perform a fitting motion, coordinating the macroscopic machine tool movement with the microscopic laser deflection to complete the overall machining of the groove. This machining method overcomes the limitations of traditional laser cutting, which can only remove layers in a single direction. It can efficiently machine complex three-dimensional curved surface structures such as spiral grooves, significantly improving machining efficiency.

[0019] Furthermore, by integrating four processing modes—laser turning, laser milling, laser cutting, and laser engraving—into a single device, each processing step is sequentially performed on the blank of the integral superhard tool without the need to change equipment or re-clamp the workpiece. This avoids the process transfers and repeated clamping required by traditional multi-device processing, allowing for one-time clamping and forming, significantly shortening the process flow and improving production efficiency and processing consistency. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic flowchart of the laser composite machining method for the integral superhard tool according to one embodiment of the present invention; Figure 2 This is a schematic diagram of turning the outer contour of the blank according to one embodiment of the present invention, wherein the direction of the triangle indicates the laser incident direction; Figure 3This is a schematic diagram of the basic shape of the cutting tool according to one embodiment of the present invention; Figure 4 for Figure 3 AA section diagram; Figure 5 This is a schematic diagram of the structure of the cutting tool according to one embodiment of the present invention; Figure 6 This is a top view of the cutting tool according to one embodiment of the present invention; Figure 7 This is a side view of the cutting tool according to one embodiment of the present invention; Figure 8 for Figure 7 Middle BB section view; Figure 9 This is a schematic diagram of the optical scalpel model according to one embodiment of the present invention, wherein the lines represent the filling trajectory of the laser beam; Figure 10 This is a schematic diagram of a cutting process based on the cutting edge structure on a cutting tool according to one embodiment of the present invention, wherein the direction of the triangle indicates the laser incident direction; Figure 11 This is a schematic diagram of engraving based on the micro-edge structure on the cutting tool according to one embodiment of the present invention, wherein the angle of the line inside the semicircle represents the incident angle of the laser beam filling. Figure 12 This is a schematic diagram of the incident filling of a light knife model by a laser beam according to one embodiment of the present invention.

[0021] in: 1. Raw material; 2. Basic shape of the cutting tool; 3. Cutting tool; 31. Groove shape; 32. Cutting edge structure; 33. Micro-cutting structure; 4. Light knife model. Detailed Implementation

[0022] To more clearly illustrate the overall concept of the present invention, a detailed description will be provided below with reference to the accompanying drawings and examples.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0024] like Figure 1 As shown, a laser composite machining method for a monolithic superhard tool involves sequentially performing the following steps on the blank 1 of the monolithic superhard tool: S100: Control the movement of the laser beam and / or control the movement of the machine tool to perform turning processing on the outer contour of the blank 1 through the laser beam to obtain a preset tool shape base 2.

[0025] This step aims to rough and semi-finish the outer contour of the cylindrical blank 1, quickly removing excess material and obtaining a precise tool shape basis 2, such as a cylindrical surface, conical surface, or spherical surface (e.g., ...). Figure 3 The contour of the rotating body (as shown) provides a precise blank reference for subsequent groove 31 and cutting edge machining.

[0026] In one embodiment, such as Figures 5 to 8 As shown, a solid four-flute end mill is used to machine polycrystalline diamond (PCD) material. The blank 1 to be machined is a cylindrical PCD diamond bar with a diameter of D10mm and a length of 75mm. The target tool 3 has a diameter of D8mm and has a spiral chip removal groove, a peripheral cutting edge, and an end cutting edge.

[0027] The blank 1 is mounted on the A / C axis rotary table clamping mechanism of the five-axis laser machining center. The measurement system is started to automatically measure the actual diameter and length of the blank 1, establish the workpiece coordinate system, and automatically compensate for installation deviations. The laser turning process module is called, and the target tool diameter is set to D8mm, which means that 1mm of material needs to be removed from one side.

[0028] During the machining process, the laser beam scans layer by layer from right to left as the workpiece rotates at high speed, completing the precision turning of the outer cylindrical surface.

[0029] It should be noted that laser turning is not only suitable for standard cylindrical surfaces, but also for machining special tool contours, such as the hemispherical contour of ball end mills, the conical surface of taper tools, and the complex rotating surfaces of forming tools. By controlling the coordination between the machine tool's motion trajectory and the laser beam, the precise forming of any rotating body contour can be completed in a single setup.

[0030] Through laser processing precision assurance technology, precision laser turning of contours such as the outer circle and curved surfaces of revolution of the laser processing cutting tool 3 can be achieved. The integral superhard tool is machined from a single piece of round bar material. First, a precise shape basis is obtained through efficient removal; otherwise, the subsequent machining of complex grooves 31 will lose its precise reference.

[0031] S200: Based on the cross-sectional parameters of the groove 31 on the tool 3, a laser beam spot pattern matching the shape of the groove cross-section is generated. The laser beam is deflected by the galvanometer system so that the laser beam fills the spot pattern. Based on the spatial parameters of the groove 31, it is mapped onto the spot pattern to form a light knife model 4 matching the shape of the groove cross-section. Based on the light knife model 4 and in conjunction with the multi-axis fitting motion of the machine tool, the milling of the tool groove 31 is completed.

[0032] This step aims to process complex three-dimensional groove features on the cutting tool 3, such as spiral chip removal grooves, coolant holes, and chip-collecting grooves. These structures have complex cross-sectional shapes and spatial orientations, which are difficult to form efficiently using traditional laser cutting.

[0033] Based on the 3D model of the helical groove of the end mill, the cross-sectional shape of the groove (31) is obtained using CAM software. The galvanometer system deflects the laser beam to generate the laser beam spot pattern, such as... Figure 4 The shaded area shown.

[0034] Based on the spatial parameters of groove 31, specifically including groove width, helix angle, and groove depth, the spatial parameters of groove 31 are obtained through scanning. The helix angle of groove 31 is then mapped onto the corresponding processing edge of the light spot pattern to obtain the torsional curvature of the processing edge of the light spot pattern. Simultaneously, this is combined with spatial parameters such as groove depth and width, mapped onto the concave-convex curvature of the light spot pattern and the edge of the pattern to form a corresponding three-dimensional light-knife model 4. Figure 9 As shown. The shape of the laser scalpel model 4 can be a circular filled shape, a small square filled shape, or an irregular filled shape. By controlling the galvanometer, the laser beam is deflected and scanned at high speed within a small area to achieve precise filling of the cross-sectional shape. For example, for the complex cross-section of a spiral groove, a multi-layer filling strategy can be adopted, so that the laser spot removes material layer by layer according to a preset trajectory.

[0035] The five-axis machine tool is controlled to drive the workpiece along a preset helical trajectory (including X-axis linear motion and A-axis rotational motion), while the galvanometer system is controlled to make the laser cutter model 4 perform high-speed deflection scanning on the workpiece surface. Through precise fitting between the macroscopic motion of the machine tool and the microscopic deflection of the laser, the laser cutter model is kept perpendicular to the surface to be processed, and the scanning trajectory is adjusted in real time according to the cross-sectional shape to complete the overall processing of the helical groove.

[0036] At this time, the laser milling process parameters are as follows: machine tool feed speed 200mm / min, laser scanning speed (i.e., the speed at which the laser spot fills inside the laser cutter model) 1500mm / s, laser power 60%, and laser frequency 300kHz.

[0037] like Figure 12 As shown, when the angle between the two tangents on the outer edge of the light-cutting model along the extension direction is less than α (set to 15° in this embodiment), it is determined that the extension direction has entered the tip region. The laser beam interval in the tip region is larger, and the machining allowance increases. Therefore, when the system recognizes that it has entered the tip region, the laser beam uses a smaller diameter spot, preferably set to a small spot with a diameter of 1 / 2 to 1 / 3 of the original diameter. The filling speed is slowed down, which can be 1 / 2 of the original filling speed, and multiple processing is performed to reduce the machining allowance. When the laser beam leaves the tip region, the original machining parameters are restored. When the groove parameters of the machining tool are different, α can be adjusted and set, usually in the range of 13° to 20°.

[0038] It should be noted that laser milling strategies are not only applicable to helical grooves, but can also be used to process other complex three-dimensional structures, such as variable pitch helical grooves, unequally divided toothed grooves, and complex cooling channels. By adjusting the coordination between the galvanometer scanning mode and the machine tool motion trajectory, the efficient forming of arbitrarily complex curved surface structures can be achieved.

[0039] The groove 31 of the integral cutting tool often has a complex spatial orientation and cross-sectional shape. The traditional laser cutting method of unidirectional layer-by-layer removal cannot efficiently process such structures. However, this step achieves one-time precise forming of complex groove 31 through the coordination of the laser cutting model and the machine tool movement.

[0040] S300: Cutting is performed by a laser beam according to the cutting edge structure 32 on the tool 3; the cutting edge structure 32 includes a tool tip, a cutting edge, and a flank face.

[0041] This step aims to precisely cut the macroscopic cutting edge structure 32, such as the tool tip, cutting edge, and flank face, to form the cutting geometry of the tool 3.

[0042] Extract the 3D model of the end mill's peripheral cutting edge, end cutting edge, and flank face, and generate layer-by-layer cutting paths, such as... Figure 10 As shown. Based on the laser processing capabilities, the cutting width and cutting depth of each step are defined. The laser beam is controlled to cut layer by layer from the outside in and from coarse to fine to ensure the precision of the cutting edge.

[0043] It should be noted that during laser cutting, the clearance angle can be precisely controlled by adjusting the laser incident angle and focal point position. For complex cutting edge structures 32 (such as drill tip chisel edges, finishing edges, etc.), multi-axis linkage can be used to adjust the angle between the laser beam and the surface to be processed, ensuring the geometric accuracy of the cutting edge. Laser cutting, through short pulses and high energy density, and angle adjustment, can control the heat-affected zone and avoid thermal damage to the tool substrate 3, making it particularly suitable for the preparation of high-precision finishing edge inserts.

[0044] The cutting edge structure 32 directly determines the cutting performance of the tool 3. It must be cut with precision to ensure its geometric accuracy and surface quality. This must be done after the aforementioned basic shape and groove 31 have been machined to ensure the positional accuracy between the features.

[0045] S400: The laser beam is controlled by the galvanometer system to keep the machine tool stationary. Based on the micro-edge structure 33 on the cutting edge structure 32, the engraving process is carried out by layer removal.

[0046] This embodiment aims to solve the precision machining problem of the micro-edge structure 33 (such as finishing edge, chip breaker groove, micro-texture, etc.) of integral superhard cutting tools. In high-speed micro-cutting, there is a serious friction and wear problem on the tool surface. By utilizing the principle of friction reduction and drag reduction of non-smooth surface micro-texture, the cutting performance of tool 3 can be effectively improved.

[0047] Although the micro-edge structure 33 is tiny (typically on the micrometer or even submicrometer scale), it has a decisive impact on the cutting performance of the tool 3: the chip breaker groove on the rake face can optimize chip morphology and improve chip removal performance; the micro-texture on the flank face can reduce the coefficient of friction and reduce cutting heat; the micro-edge in the cutting edge transition zone can improve cutting sharpness and improve the surface quality of the machined part. Machining a micro-edge structure on the surface of the tool 3 can significantly improve the cutting performance and service life of the tool 3.

[0048] It should be noted that during the engraving process, the machine tool axes remain stationary, and the laser beam is controlled by the galvanometer system to quickly scan and engrave the target processing area in the normal direction.

[0049] The micro-edge structure 33 is extremely small (typically on the micrometer scale). If machine tool motion is used for machining, the machine tool's minute feed error, motion inertia, and vibration will directly affect the machining accuracy. However, the galvanometer system controls the laser beam through the high-speed deflection of the mirror, which can achieve precise positioning at the micrometer or even sub-micrometer level, and has no mechanical inertia limitations, making it particularly suitable for precision machining of tiny features.

[0050] Through precise control of the galvanometer system, complex microstructures can be precisely shaped on the surface of the tool 3. Similarly, a layered removal method is used to transform the three-dimensional micro-edge structure model into a series of two-dimensional layers, which are then engraved layer by layer. Specifically: when the tool 3 has a micro-edge structure 33, after cutting, the process further includes: The number of layers is determined based on the total depth of the micro-blade structure 33 and the processing capacity of a single layer. For example, for a micro-texture with a depth of 10 μm, if the processing depth of a single layer is set to 0.001-0.01 mm (i.e., 1-10 μm), it can be divided into 1-10 layers.

[0051] The process involves layer-by-layer processing control. Based on the two-dimensional cross-sectional data of each layer, the control system generates a laser scanning path and controls the galvanometer to rapidly scan the target area with the laser beam. After completing one layer, the system automatically switches to the next layer until all layers are processed.

[0052] Precise layer thickness control is achieved by precisely adjusting laser parameters (power, frequency, pulse width, etc.) and the depth of layering, thus avoiding thermal damage and obtaining a defect-free, high-smooth surface.

[0053] Furthermore, it should be noted that the machinable micro-blade structures 33 include, but are not limited to, the following types: The micro-edge structure, which processes micron-sized cutting edges on the cutting edge, can improve the cutting sharpness of tool 3 and is suitable for precision micro-machining applications; The chip breaker groove structure, with microgrooves machined on the rake face, can optimize chip morphology, improve chip removal performance, and prevent long chips from wrapping around the tool and workpiece. Microtexture refers to the machining of regularly arranged microstructures such as pits and grooves on the rake face, flank face, or edge transition zone. Both microgroove and micropit textures can effectively reduce the surface friction coefficient of the cutting tool; in high-speed micro-cutting, they can reduce cutting force and cutting temperature, shorten the chip contact length, and improve chip morphology. In particular, micropit textures can significantly improve surface quality. By refining the cutting edge structure and machining fine structures in the transition zone of the cutting edge, the surface finish of the machined surface is improved. Studies have shown that machining micro-textures on the flank face can effectively reduce friction with the machined surface and improve surface quality. Micro-nano composite structures combine micron-scale structures and nano-scale laser-induced periodic surface structures to form composite functional surfaces.

[0054] In a preferred embodiment of the present invention, when turning the outer contour of the blank 1, a layered step-by-step machining method is adopted, including: The number of turning layers is determined based on the radius of the blank 1 and the target machining radius of the tool 3; Based on the number of turning layers, select the incident position of the laser beam relative to the workpiece, and / or, Determine the number of repeated turning operations for each layer, and / or, Match laser parameters.

[0055] This implementation aims to solve two core problems in laser turning of integral superhard tools: first, the balance between the amount of material removed from the blank 1 and the machining accuracy; and second, the problem of uneven machining allowance caused by the dimensional deviation of the blank 1.

[0056] By using layered step-by-step machining, precise control of the material removal process is achieved, ensuring both high efficiency in the roughing stage and high precision in the finishing stage. At the same time, repeated turning eliminates the impact of blank deviation.

[0057] Determining the number of turning layers is fundamental to layered step-by-step machining. The specific implementation is as follows: The number of turning layers is determined based on the radius of the blank 1 and the target machining radius of the tool 3, specifically as follows: Based on the radius of the blank 1 and the target machining radius of the tool 3, and in conjunction with the turning layer thickness, the number of turning layers is determined. From the outside in, as the number of machining layers increases, the thickness of the machining layer decreases.

[0058] The single-layer removal capability achievable by the laser is determined based on the laser power and frequency, i.e., the maximum feed rate Δd per layer during turning. This is achieved by using a given blank radius. and the radius of the planned processing location From this, we can derive the total remaining amount Δ to be removed from the planned vehicle. .

[0059] In laser layer removal technology, the thickness of each layer, i.e., the focal drop distance, affects the actual ablation depth and significantly impacts the processing quality. If the preset layer thickness does not match the actual removal capacity, it will lead to reduced processing efficiency or decreased surface quality.

[0060] The outer layer uses a relatively large layer thickness to achieve rapid material removal and improve processing efficiency. For example, the initial outer layer thickness can be set to 0.01 mm / layer. As processing progresses inward, the layer thickness is gradually reduced, for example, to 0.005 mm / layer, improving processing accuracy while maintaining a certain level of efficiency. The innermost layer uses an extremely small layer thickness, such as 0.001 mm / layer, to achieve high-precision processing and ensure final dimensional accuracy and surface quality.

[0061] Solid superhard cutting tools are machined from a single block of round bar material, with a large machining allowance and high precision requirements. If a single layer thickness is used for machining, either the layer thickness is too large, resulting in insufficient precision in the finishing stage, or the layer thickness is too small, resulting in low efficiency in the roughing stage. This application achieves efficient removal in the roughing stage and ensures machining accuracy in the finishing stage, thus balancing the dual requirements of efficiency and quality.

[0062] Specifically, given a blank radius of 5mm, a target radius of 4mm, and a single-sided removal amount of 1mm, the processing can be divided into three stages: outer layer 0-0.5mm: layer thickness 0.01mm, totaling 50 layers; middle layer 0.5-0.8mm: layer thickness 0.005mm, totaling 60 layers; inner layer 0.8-1.0mm: layer thickness 0.001mm, totaling 200 layers. The total number of processed layers is 50+60+200=310 layers, providing a precise layering basis for subsequent incident position selection, repetition count setting, and laser parameter matching.

[0063] It should be noted that the layer thickness can be gradually reduced from the outside to the inside based on the number of processing layers, or the layer thickness of the next layer can be adjusted based on the processing precision of the previous layer; there are no restrictions on this.

[0064] Example 1: Based on the number of turning layers, the incident position of the laser beam relative to the blank 1 is selected, specifically as follows: At least the outermost turning layer is cut using half-tangential incident cutting or perpendicular irradiation cutting. At least the innermost turning layer uses tangential incident cutting. From the outside in, the incident position changes from semi-tangential incident cutting or perpendicular irradiation cutting to tangential incident cutting. The change of incident position is achieved by moving the blank 1 radially relative to the laser beam, and / or, This is achieved by moving the laser beam relative to the blank 1 along the radial direction of the blank 1.

[0065] In the outermost turning layer (i.e., the roughing stage), the material removal is large and the machining allowance is uneven. The primary goal is to achieve rapid material removal and improve machining efficiency. Using vertical irradiation cutting or half-phase tangential incident cutting can achieve strong machining capabilities and high material removal rates.

[0066] like Figure 2 As shown, perpendicular irradiation cutting refers to laser beam irradiation direction perpendicular to the rotation axis of blank 1 and pointing towards the center of blank 1. Under this incident mode, the laser spot energy completely irradiates the surface of blank 1, and the energy density reaches its maximum value. When the laser irradiates the material surface perpendicularly, the material's absorption rate of the laser is the greatest, and the reflection is the least. The laser energy can be coupled into the material interior more effectively, resulting in the strongest processing capability and the highest efficiency.

[0067] Semi-tangential incident cutting falls between perpendicular irradiation and tangential irradiation. The laser beam is at a certain angle to the surface of the blank 1, but not tangential. This incident method can achieve better surface quality than perpendicular irradiation while maintaining high processing efficiency.

[0068] In the innermost turning layer (i.e., the finishing stage), the amount of material removed is small, and the requirements for surface quality and dimensional accuracy are high. Tangential incident cutting can achieve better surface quality.

[0069] Tangential incident cutting refers to laser beams that are tangential to the outer circle of the blank 1, meaning the direction of the laser beam is consistent with the tangential direction of the blank 1 surface. Under this incident method, the laser spot is elongated on the material surface, reducing the energy density, which is beneficial for achieving micro-removal; at the same time, the lower energy density and wider processing range help to obtain more uniform material removal and reduce surface defects.

[0070] Figure 2 The middle triangle indicates the incident direction of the laser beam, and from right to left, they represent three cutting methods: tangential incident cutting, semi-tangential incident cutting, and perpendicular irradiation cutting.

[0071] As the turning process progresses layer by layer from the outside in, the radius of the blank 1 gradually decreases. Based on the radius of the blank 1 corresponding to the current machining layer, the radial position of the laser beam is adjusted in real time to ensure that the laser beam always acts on the surface of the blank 1 in a preset incident manner.

[0072] For example, during initial processing, the laser beam is aligned with the center of the blank 1 (perpendicular illumination); after processing reaches a predetermined number of layers, the control system controls the laser beam to move radially outward a certain distance, causing the laser beam to deviate from the center position and form an incident state that is tangential or semi-tangential to the blank 1. This radial relative movement can be achieved through the X-axis or Y-axis movement of the machine tool, or by deflecting the laser beam through a galvanometer system.

[0073] Example 2: Based on the number of turning layers, determine the number of times each layer needs to be repeatedly turned, specifically as follows: The outermost machining layer should be machined at least once. From the outside in, as the number of machining layers increases, the number of repeated machining operations also increases.

[0074] To prevent large discrepancies in blank material and inconsistent allowances, and to ensure machining results, the number of repeated machining operations for each layer can be set, and machining can be performed layer by layer in a step-by-step manner.

[0075] The outermost turning layer should be turned at least once. From the outside in, the number of turning layers increases accordingly.

[0076] During the outer layer processing, the amount of material removed is large, and the problem of uneven allowance is quite prominent. Appropriately increasing the number of repetitions can ensure that the dimensions are uniform after each layer is processed. During the inner layer finishing process, the accuracy requirements are even higher. By increasing the number of repetitions, minute corrections can be made to gradually approach the target size.

[0077] In laser processing, the number of repetitions refers to the number of times the same processing area is processed repeatedly. Increasing the number of repetitions allows for deeper processing or achieves higher precision. By setting the number of repeated turning operations, even if the blank 1 has certain dimensional deviations, the influence of these deviations can be eliminated through multiple step-by-step turning operations, ensuring the final processing accuracy.

[0078] Example 3: Matching laser parameters according to the number of turning layers, specifically: From the outside in, the laser energy decreases as the number of machining layers increases.

[0079] To improve processing efficiency, laser parameters are dynamically matched during the turning process. From the outside in, the laser energy gradually decreases as the number of turning layers increases.

[0080] For example, in the initial roughing stage, to improve turning efficiency, a large laser energy (such as 80% laser power) is used to achieve rapid removal of 0.5mm in the first stage; as the machining progresses to the inner layer, the laser energy is gradually reduced, and in the final finishing stage, a low laser energy (such as 20% laser power) is used to achieve high-precision machining with a removal of 0.001mm.

[0081] By dynamically adjusting the laser power and frequency, better processing results can be achieved at different processing stages. For example, when the laser is cutting at a corner, pulsed lasers should be used as much as possible and the duty cycle should be reduced to avoid overheating due to excessive heat concentration.

[0082] It should be noted that dynamic matching of laser parameters includes not only laser power, but also the coordinated adjustment of parameters such as laser frequency and pulse width.

[0083] As a preferred embodiment of the present invention, based on the light-cutting knife model 4 and simultaneously coordinating with the multi-axis fitting motion of the machine tool, specifically: Based on the tool shape base 2 and the cross-section of the tool 3, the area to be removed that matches the groove shape 31 is determined, and the light spot pattern is obtained; Based on the groove width, helix angle, and groove depth of the groove 31, the light spot pattern is mapped to generate a laser cutter model 4. Based on the model parameters of the laser cutter model 4, the multi-axis fitting motion of the machine tool is adjusted to perform laser milling of the groove 31.

[0084] This embodiment aims to solve the problem of laser milling complex three-dimensional grooves (such as helical chip removal grooves, coolant holes, and chip-receiving grooves) using integral superhard cutting tools. In three-dimensional curved surface laser machining, it is difficult to achieve efficient and precise forming of complex grooves by relying solely on machine tool motion or solely on galvanometer scanning. This embodiment constructs a laser cutting tool model 4 that matches the groove cross-section and combines it with the fitted motion curvature of the machine tool based on the helix angle to achieve coordinated control of macroscopic motion and microscopic deflection.

[0085] After laser turning is completed, tool 3 has obtained a precise outer cylindrical surface or surface of revolution shape. This shape shape is the spatial reference for slot machining, which determines the distribution position and depth range of the slot on the tool circumference.

[0086] Based on the tool design model, a cross-sectional view perpendicular to the tool axis is obtained. In the cross-sectional view, the area where material to be removed between the outer contour of the tool and the groove 31 to be machined can be clearly identified, such as... Figure 4 The shaded area is shown. Based on the cross-sectional view, the boundary contour of the area to be removed is extracted using CAM software. This contour typically consists of the outer contour arc of the tool, the bottom arc of the groove, and the transition curves on both sides, forming a closed two-dimensional graphic area.

[0087] For the area to be removed, a laser beam scanning path is generated using a grid filling, ring filling, or adaptive filling algorithm. The filling spacing is typically set to 30-50% of the spot diameter to ensure appropriate overlap between adjacent scan lines and avoid processing lines or residual unprocessed areas.

[0088] The laser beam is deflected by a galvanometer system, causing it to move at high speed along a generated filling trajectory, forming a light-cutting model 4 that matches the cross-sectional shape of the groove to be processed. It can be understood that by controlling the galvanometer deflection, the light-cutting model 4 can present circular, square, or irregular filling patterns to adapt to the geometric characteristics of different groove cross-sections. The size of the light-cutting model 4 can be dynamically adjusted according to the groove size; a small-diameter light-cutting model is used for small-sized grooves, while a large-diameter light-cutting model can be used for large-sized grooves to improve efficiency. Furthermore, by adjusting the matching relationship between the galvanometer scanning speed and the laser power, the spatial distribution of energy within the light-cutting model can be controlled.

[0089] The curvature of the machine tool's fitted motion is formed based on the helix angle of groove 31. The helix angle is a key geometric parameter of the helical groove, determining the degree of twisting of the groove along the tool axis. In five-axis laser machining, the motion trajectory of each axis of the machine tool needs to be precisely planned according to the surface characteristics of the workpiece to ensure that the laser beam always acts on the machining surface at the optimal angle.

[0090] The helix angle refers to the angle between the helical groove and the tool axis, typically ranging from 15° to 45°. A larger helix angle results in more severe axial torsion of the groove, placing higher demands on the multi-axis linkage of the machine tool. Based on the helix angle parameters, CAM software generates the motion trajectories for each axis of the machine tool. For a standard helical groove, the motion trajectory can be decomposed as follows: X-axis motion is linear motion along the tool's 3-axis direction; A-axis (or C-axis) rotational motion is rotational motion around the tool's axis, and the ratio of the rotational speed to the X-axis feed speed is determined by the helix angle.

[0091] For variable helix angle grooves or non-uniform helix grooves, the motion curvature needs to be continuously adjusted according to the rate of change of the helix angle to ensure that the relative position and angle between the polishing knife model 4 and the workpiece surface are always optimal.

[0092] The five-axis machine tool controls the workpiece to move along a preset spatial trajectory to determine the overall direction of the groove. The galvanometer system controls the light knife model to scan the workpiece surface at high speed to complete the precise filling of the cross-sectional shape. The control system fits the macroscopic motion and microscopic deflection in real time to achieve one-time forming of complex grooves.

[0093] Specifically, taking the machining of a helical groove on a solid PCD four-flute end mill as an example, laser turning has been completed. The tool diameter is D8mm, and the cylindrical surface accuracy is ±0.002mm. The groove helix angle is 30°, the groove depth is 1.2mm, the bottom arc radius is 0.5mm, and the four grooves are evenly distributed.

[0094] At this point, extract a cross-sectional view perpendicular to the tool axis to identify the area to be removed, such as... Figure 4The shaded area is shown. A grid fill method is used with a fill spacing of 0.015mm, and the fill direction is parallel to the bottom arc of the groove. The shape of the light-cutting model is an irregularly shaped fill pattern, with dimensions precisely matching the groove cross-section.

[0095] Based on a helix angle of 30°, the motion curvature is calculated, and the ratio of the X-axis feed rate to the A-axis rotational speed is cot(30°) = 1.732. Setting the X-axis feed rate to 200 mm / min, the A-axis rotational speed is approximately 115.5° / min. For a four-groove configuration, after machining one groove, the C-axis rotates 90° to enter the next groove.

[0096] The machine tool controls the workpiece to move along a helical trajectory (X-axis linear motion + A-axis rotational motion), while the galvanometer system controls the polishing die model to deflect and scan the workpiece surface at high speed, removing material layer by layer according to a preset filling trajectory. The control system fits the motion of both in real time to ensure that the polishing die model is always perpendicular to the machining surface.

[0097] In a preferred embodiment of the present invention, cutting is performed using a laser beam based on the cutting edge structure 32 on the tool 3, specifically as follows: Based on the cutting edge structure 32 on the tool 3, and combined with laser processing capabilities, the cutting width and cutting depth of each step are defined. The incident direction of the laser beam is controlled from the outside to the inside, and from the direction perpendicular to the axis of the tool 3 to the inclined direction of the cutting edge structure 32, so as to perform layer-by-layer cutting.

[0098] This embodiment aims to solve the problem of precision forming of the cutting edge structure 32 (including the tool tip, cutting edge, and flank face) of a monolithic superhard cutting tool. The cutting edge structure 32 directly determines the cutting performance of the tool 3, and its geometric accuracy and surface quality have a decisive influence on the surface finish of the machined workpiece, the tool life, and the cutting stability.

[0099] At the microscopic level, the cutting edge obtained by traditional grinding or electrical discharge wire cutting often exhibits a serrated line with a width and depth of more than 3μm. On the one hand, this makes the cutting edge prone to chipping and breaking during processing and reduces tool life. On the other hand, it leaves microscopic bumps and grooves on the surface of the workpiece, thus leaving machining marks and affecting the processing effect.

[0100] Laser layer-by-layer cutting technology can achieve precise shaping of the cutting edge structure 32, resulting in a smooth, sharp cutting surface while avoiding microscopic defects caused by traditional processing methods. For example... Figure 10 As shown, by controlling the angle of the laser beam and converting it to tilt towards the cutting edge along the direction perpendicular to the axis of the tool 3, precise shaping of the cutting edge geometry can be achieved, avoiding overheating and thermal damage, and improving the quality of the cutting edge.

[0101] Cut width refers to the width of the laser's single cutting path, typically corresponding to the laser spot diameter or the width of the cutting band formed by galvanometer scanning. Cut depth refers to the amount of material removed in the thickness direction during a single laser cut.

[0102] As a preferred embodiment of this implementation, the cutting width and cutting depth of each step are defined as follows: From the outside in, as the number of cutting layers increases, the cutting width and cutting depth decrease.

[0103] Specifically, based on the final required 3D model of the cutting edge, CAM software is used to generate layer-by-layer cutting paths. The cutting path progresses gradually from the outside in, that is, it starts from the area far from the final cutting edge contour and gradually approaches the cutting edge contour.

[0104] For example, in peripheral cutting of an end mill, the excess material on the outer side of the cutting edge is cut first, and then the cutting proceeds inward until the final cutting edge and flank face are formed. This outward-to-inward cutting strategy ensures that each cut has a clear material removal boundary, avoiding overcutting or undercutting due to improper cutting sequence.

[0105] The three-dimensional model of the cutting edge structure 32 is decomposed into a series of two-dimensional cutting layers, each corresponding to a specific cutting depth. The control system controls the laser beam to perform the cutting operation layer by layer according to the preset cutting depth.

[0106] In the initial cutting stage, a larger cutting width and depth are used in the outermost layer, in the area far from the cutting edge contour, to quickly remove excess material. This stage primarily focuses on processing efficiency, with relatively relaxed requirements for precision. A relatively large cutting depth (e.g., 0.005-0.01 mm / layer) and a larger cutting width (which can be defined as 0.2-0.5 mm) are used to achieve rapid material removal and improve processing efficiency.

[0107] As the cutting approaches the edge profile, the depth of cut is gradually reduced, and a smaller cutting width is used to improve dimensional control accuracy and ensure the geometric accuracy of the cutting edge.

[0108] In the final shaping stage, a very small cutting depth (such as 0.001-0.002 mm / layer) is used in the last few layers of cutting, and the cutting width can be reduced to 0.05-0.1 mm to achieve precise shaping of the cutting edge and ensure surface quality and geometric accuracy.

[0109] Furthermore, the incident direction of the laser beam is determined based on design parameters such as the blade inclination angle of the cutting edge structure 32. To obtain a three-dimensional cut workpiece with good kerf quality, high cutting accuracy, and a small heat-affected layer, the incident angle of the laser beam should be kept as small as possible to less than 20°. When the incident angle is within the critical angle, it has little effect on the kerf width, surface roughness, and surface ripples; however, exceeding this critical angle will significantly reduce the cutting quality.

[0110] In the outer layer, along the direction perpendicular to the tool axis, a high energy density is maintained to achieve rapid removal. In the innermost layer, a precisely matched cutting edge angle is used, with the laser beam angle perfectly matching the cutting edge tilt angle of the cutting edge structure 32, ensuring cutting edge geometric accuracy and achieving one-time precise forming.

[0111] In a preferred embodiment of the present invention, engraving processing includes: In adjacent engraving layers, the laser beam engraving scans in different directions; The direction of the laser beam engraving scan includes at least one of 0°, 45°, 90°, and 135°.

[0112] like Figure 11 As shown, changing the scanning and filling direction of the laser beam when engraving different layers can effectively reduce the accumulation of defects caused by processing in a single direction. Adjusting the laser beam filling angle layer by layer can disrupt the heat flow direction, refine grains, homogenize stress, and improve surface quality. The angle of the semi-circular shaded filling line in the figure indicates the angle of laser beam incidence. Specifically: The first layer uses a 0° direction scan (parallel to a certain reference direction); The second layer uses a 45° scanning direction; The third layer uses a 90° directional scan (perpendicular to the direction of the first layer); The fourth layer uses a 135° scanning direction; The above cycle can be repeated or more directional combinations can be used as needed.

[0113] At this point, it should be noted that adjacent carving layers refer to carving and processing layers that are structurally close to each other. That is, the adjacent carving layer of the first layer is the second layer; the adjacent carving layers of the second layer are the first and third layers.

[0114] Laser focal spot shaping using a spatial light modulator allows for precise focusing of femtosecond lasers onto material surfaces for direct writing, enabling accurate control of complex paths. During laser scanning, material removal along the scanning direction differs from removal perpendicular to it. In unidirectional scanning, this anisotropy causes surface textures to distribute along a specific direction, forming regular groove-like morphologies. By changing the scanning direction, the defect distribution directions of adjacent layers can differ, compensating for each other and resulting in a more uniform surface.

[0115] Furthermore, the convergence of laser beams during synchronous scanning leads to increased heat accumulation and a reduced cooling rate, resulting in grain coarsening. However, using layered scanning in different directions can effectively disperse heat accumulation, allowing heat to diffuse more evenly throughout the material and preventing surface defects caused by localized overheating.

[0116] The second invention provides a laser composite machining system for integral superhard cutting tools, used to implement the method, comprising: Five-axis motion machine tools are used to drive workpieces to achieve multi-axis linkage motion; A galvanometer system, including a laser, a mirror, a beam expander, a galvanometer, and a focusing mirror, is used to generate and control a laser beam; The control system is used to coordinate and control the motion trajectory of the five-axis machine tool and the laser deflection of the galvanometer system to achieve the switching and processing of turning, milling, cutting and engraving.

[0117] Therefore, the laser composite machining method that can achieve any effect in integral superhard tools will not be elaborated here.

[0118] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0119] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0120] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A laser composite machining method for integral superhard cutting tools, characterized in that, The following steps are performed sequentially on the blank (1) of the integral superhard tool: Control the movement of the laser beam and / or control the movement of the machine tool to perform turning processing on the outer contour of the blank (1) through the laser beam to obtain a preset tool shape basis (2). According to the cross-sectional parameters of the groove (31) on the tool (3), a laser beam spot pattern matching the shape of the groove cross-section is generated. The laser beam is deflected by the galvanometer system so that the laser beam fills the spot pattern. According to the spatial parameters of the groove (31), it is mapped to the spot pattern to form a light knife model (4) matching the shape of the groove cross-section. According to the light knife model (4) and in conjunction with the multi-axis fitting motion of the machine tool, the milling of the tool groove (31) is completed. The laser beam is used to perform cutting based on the cutting edge structure (32) on the tool (3); the cutting edge structure (32) includes the tool tip, the cutting edge, and the flank face; The laser beam is controlled by a galvanometer system to keep the machine tool stationary. Based on the micro-blade structure (33) on the cutting edge structure (32), the engraving process is carried out by layer removal.

2. The method according to claim 1, characterized in that, When turning the outer contour of the blank (1), a layered step-by-step machining method is adopted, including: The number of turning layers is determined based on the radius of the blank (1) and the target machining radius of the tool (3); Based on the number of turning layers, select the incident position of the laser beam relative to the blank (1), and / or, Determine the number of repeated turning operations for each layer, and / or, Match laser parameters.

3. The method according to claim 2, characterized in that, The number of turning layers is determined based on the radius of the blank (1) and the target machining radius of the tool (3), specifically as follows: Based on the radius of the blank (1) and the target machining radius of the tool (3), and in conjunction with the turning layer thickness, the number of turning layers is determined. From the outside in, as the number of machining layers increases, the thickness of the machining layer decreases.

4. The method according to claim 2, characterized in that, Based on the number of turning layers, the incident position of the laser beam relative to the blank (1) is selected as follows: At least the outermost turning layer is cut using half-tangential incident cutting or perpendicular irradiation cutting. At least the innermost turning layer uses tangential incident cutting. From the outside in, the incident position changes from semi-tangential incident cutting or perpendicular irradiation cutting to tangential incident cutting. The change of incident position is achieved by moving the blank (1) radially relative to the laser beam, and / or, This is achieved by moving the laser beam radially relative to the blank (1).

5. The method according to claim 2, characterized in that, Based on the number of turning layers, determine the number of times each layer will be repeatedly turned, and match the laser parameters accordingly, specifically: The outermost machining layer should be machined at least once. From the outside in, as the number of machining layers increases, the number of repeated machining operations also increases. From the outside in, the laser energy decreases as the number of machining layers increases.

6. The method according to claim 1, characterized in that, Based on the aforementioned light-cutting knife model (4) and simultaneously in conjunction with the multi-axis fitting motion of the machine tool, the specific details are as follows: Based on the tool shape base (2) and the cross section of the tool (3), the area to be removed that matches the groove shape (31) is determined to obtain the spot pattern; Based on the groove width, helix angle and groove depth of the groove (31), the light spot pattern is mapped to generate a light knife model (4). Based on the model parameters of the light knife model (4), the multi-axis fitting motion of the machine tool is adjusted to perform laser milling of the groove (31).

7. The method according to claim 1, characterized in that, Cutting is performed using a laser beam based on the cutting edge structure (32) on the tool (3), specifically as follows: Based on the cutting edge structure (32) on the cutting tool (3), and combined with the laser processing capability, the cutting width and cutting depth of each step are defined. The incident direction of the laser beam is controlled from the outside to the inside, and from the direction perpendicular to the axis of the tool (3) to the inclined direction of the cutting edge of the cutting edge structure (32) to perform layer-by-layer cutting.

8. The method according to claim 7, characterized in that, Define the cut width and depth of cut for each step as follows: From the outside in, as the number of cutting layers increases, the cutting width and cutting depth decrease.

9. The method according to claim 1, characterized in that, Carving and engraving processes include: In adjacent engraving layers, the laser beam engraving scans in different directions; The direction of the laser beam engraving scan includes at least one of 0°, 45°, 90°, and 135°.

10. A laser composite machining system for an integral superhard cutting tool, characterized in that, For implementing the method according to any one of claims 1 to 9, comprising: Five-axis motion machine tools are used to drive workpieces to achieve multi-axis linkage motion; A galvanometer system, including a laser, a mirror, a beam expander, a galvanometer, and a focusing mirror, is used to generate and control a laser beam; The control system is used to coordinate and control the motion trajectory of the five-axis machine tool and the laser deflection of the galvanometer system to achieve the switching and processing of turning, milling, cutting and engraving.

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