Method for keeping cutting edge in rear tool face graphenization and diamond tool workpiece

Abstract

The invention provides a method for keeping a cutting edge in graphenization of a rear tool face and a diamond tool workpiece. The method comprises the following steps that S1, a diamond tool is clamped; s2, filling, scanning and ablating are conducted on the rear tool face of the diamond tool; s3, the diamond cutter obtained in the step S2 is subjected to annealing treatment; and S4, the diamond cutter obtained in the step S3 is subjected to lossless cleavage treatment, and rear cutter face graphenization is completed. According to the method for keeping the cutting edge in the rear tool face graphenization and the diamond tool workpiece, the rear tool face of the diamond tool is induced to generate phase change, then annealing is conducted in the air to remove an amorphous phase change layer, and finally the diamond tool is placed in the solution to be subjected to lossless cleavage treatment to conduct in-situ cleavage on an oriented phase change layer to form graphene. Graphene can be directly and accurately realized on the rear cutter surface of the diamond cutter, and the sharpness of the cutting edge of the cutter is ensured.

Description

Technical Field

[0001] This invention relates to the field of cutting tool manufacturing technology, and more specifically, to a method for maintaining the cutting edge during graphene formation of the flank face and to diamond cutting tool components. Background Technology

[0002] Driven by the rapid development of modern science and technology, cutting-edge fields such as aerospace, microelectromechanical systems (MEMS), biomedical engineering, and nuclear energy technology have placed increasingly stringent demands on the processing performance of materials. With the widespread use of a series of new, difficult-to-machine materials such as carbon fiber reinforced composites, advanced high-temperature alloys, and titanium-based alloys, traditional high-speed steel and cemented carbide tools can no longer meet current requirements in terms of processing efficiency and surface quality. Diamond, due to its extremely high hardness, excellent thermal conductivity, and superior wear resistance, is considered an ideal superhard tool material, exhibiting significant advantages in precision machining and the processing of special materials.

[0003] However, despite the excellent performance of diamond tools in machining a variety of difficult-to-machine materials, several key technical bottlenecks remain in their application to cutting novel, difficult-to-machine materials such as those used in aerospace. Specifically, when machining new, difficult-to-machine materials, the diamond surface is prone to amorphization under high cutting forces, affecting tool life. Furthermore, under dry cutting conditions, the frictional state at the tool-workpiece interface deteriorates sharply, further limiting its machining performance. When machining ferrous metals, diamond readily reacts chemically with iron-based elements, leading to premature tool wear. These problems severely restrict the promotion and application of diamond tools in ultra-precision cutting of ferrous metals and high-quality, high-efficiency milling of carbon fiber composites.

[0004] Graphene, a two-dimensional material discovered at the beginning of this century, possesses many revolutionary properties and is considered to have broad prospects in future material modification. In-situ graphene modification of the surface of diamond cutting tools is expected to significantly improve their service life and overall cutting performance. Currently, although in-situ graphene modification of the rake face can be achieved through pre-preparation in situ on the diamond sheet, when performing similar treatment on the flank face of the finished tool, existing processes still struggle to avoid damaging the edge sharpness, thereby weakening the core cutting capability of the diamond tool.

[0005] Therefore, how to achieve in-situ graphene modification on the surface of diamond tools while maintaining the geometric integrity and sharpness of the cutting edge has become one of the key technical challenges in promoting the performance upgrade of diamond tools.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for maintaining the cutting edge during graphene formation on the flank face of a diamond tool and a diamond tool component. This method allows for precise graphene formation directly on the flank face of the diamond tool while ensuring the sharpness of the cutting edge.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A method for maintaining the cutting edge during graphene formation on the flank of a cutting tool includes the following steps: Step S1: Clamp the diamond tool; Step S2: Perform fill scanning ablation on the back face of the diamond tool; Step S3: Anneal the diamond tool obtained in step S2; Step S4: Perform non-destructive cleavage treatment on the diamond tool obtained in step S3, and then graphene-coated the tool surface.

[0009] Furthermore, in step S2, laser is used for fill scanning ablation. The conditions for fill scanning ablation are: laser pulse width ≥ 1ps; spot overlap rate ≥ 90%; laser single pulse energy density * (sinθ)^2 ≥ graphitization threshold of diamond surface.

[0010] Further, in step S1, the diamond tool is clamped on a rotating platform, and the rotation angle is adjusted to adjust the angle between the back face of the diamond tool and the laser incident direction.

[0011] Furthermore, the rotation axis of the rotating platform is perpendicular to the laser incident direction.

[0012] Furthermore, the angle θ between the back face of the diamond tool and the incident direction of the laser is 1~20°, preferably 5~15°.

[0013] Furthermore, in step S2, the flank face of the diamond tool is filled by scanning ablation to form a phase transformation layer on the flank face of the diamond tool, thereby obtaining a diamond tool with a phase transformation layer on the flank face.

[0014] Furthermore, in step S2, the direction of the filling scan is parallel to the cutting edge, and the filling scan starts from the direction away from the cutting edge and moves towards the cutting edge.

[0015] Furthermore, the phase change layer includes an amorphous phase change layer and an oriented phase change layer, and the phase change layer in contact with air is the amorphous phase change layer.

[0016] Furthermore, the thickness of the amorphous phase transition layer is 0.01~5μm, preferably 0.05~2μm.

[0017] Furthermore, the thickness of the orientation phase change layer is 0.01~2μm, preferably 0.1~1μm.

[0018] Furthermore, in step S3, the diamond tool with a phase transformation layer on the back face is annealed to remove the amorphous phase transformation layer, resulting in a diamond tool without an amorphous phase transformation layer on the back face.

[0019] Furthermore, the annealing conditions in step S3 are as follows: the annealing temperature is 400~600℃, preferably 400~500℃; the annealing time is 2~6h, preferably 2~4h.

[0020] Furthermore, in step S3, the annealing process is carried out in an air atmosphere, and the cooling method is natural cooling in the air.

[0021] Furthermore, the non-destructive cleavage treatment in step S4 includes at least one of ultrasonic treatment, intercalation stripping treatment, and redox treatment.

[0022] Furthermore, in step S4, the diamond tool without an amorphous phase change layer on the back face is placed in a solution for non-destructive cleavage treatment, so that the orientation phase change layer on the back face is cleaved in situ into graphene, and the tool face is then grapheneized.

[0023] Furthermore, the non-destructive cleavage treatment in step S4 is ultrasonic treatment. The conditions for ultrasonic treatment are: time 2~6h, preferably 4~6h; temperature 40~60℃, preferably 45~55℃; power 10~40W, preferably 20~40W.

[0024] Further, the solution in step S4 is at least one of N-methylpyrrolidone solution, sodium dodecylbenzenesulfonate solution, and ethanol-propanol mixture; preferably N-methylpyrrolidone solution.

[0025] Further, in step S4, the angle between the graphene sheet in the graphene and the back face of the diamond tool is independently 30~150°, preferably 60~120°; the angle between adjacent single graphene sheets is independently 0~90°, preferably 0~30°; the height of a single graphene sheet is independently 0.01~2μm, preferably 0.1~1μm, and the lateral dimension is independently 0.01~2μm, preferably 0.1~1μm; the number of layers in a single graphene sheet is independently 1~20 layers, preferably 1~10 layers.

[0026] The diamond tool components obtained by the above-mentioned method of maintaining the cutting edge during graphene formation on the flank face include diamond tools with a phase change layer on the flank face obtained in step S2, diamond tools without an amorphous phase change layer on the flank face obtained in step S3, and diamond tools with the oriented phase change layer on the flank face in situ cleaved into graphene obtained in step S4.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The method for maintaining the cutting edge during graphene formation on the flank face of the diamond tool and the diamond tool component of the present invention can directly and accurately achieve graphene formation on the flank face of the diamond tool and ensure the sharpness of the cutting edge.

[0028] 2. The method for maintaining the cutting edge during graphene formation on the flank face of the present invention is simple to operate, has high processing efficiency and low cost, and is conducive to its widespread application. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the process of using laser to fill and scan the back face of the cutting tool in this invention; Figure 2 This is a scanning electron microscope image of the diamond tool with no amorphous phase transformation layer on the back face obtained in Example 1; Figure 3 The image shows a scanning electron microscope (SEM) image of a diamond tool obtained in Example 1, in which the remaining orientation-state phase change layer on the back face is cleaved into graphene in situ. Figure 4 The cutting edge blunt circle radius of the diamond tool with the orientation state phase change layer on the back face in situ cleaved into graphene, prepared in Example 1; Figure 5 This is a diagram showing the blunt radius of the cutting edge of the original diamond tool in Example 1. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0032] A method for maintaining the cutting edge during graphene formation on the flank of a cutting tool includes the following steps: Step S1: Clamp the diamond tool; Step S2: Perform fill scanning ablation on the back face of the diamond tool; Step S3: Anneal the diamond tool obtained in step S2; Step S4: Perform non-destructive cleavage treatment on the diamond tool obtained in step S3, and then graphene-coated the tool surface.

[0033] Preferably, in step S2, a laser is used for filling scanning ablation, and the laser induces a phase transformation on the back face of the diamond tool.

[0034] Preferably, in step S1, the diamond tool is clamped on a rotating platform, and the rotation angle is adjusted to adjust the angle between the back face of the diamond tool and the laser incident direction.

[0035] Preferably, the rotation axis of the rotating platform is perpendicular to the laser incident direction.

[0036] Preferably, the flank face of the diamond tool is at a small angle to the laser incident direction, with the angle θ being 1~20° (including but not limited to 1°, 5°, 10°, 15°, 20°), preferably 5~15°. An excessively large angle will result in a greater ablation depth and heat-affected area during laser ablation, causing damage to the sharp cutting edge; an excessively small angle will prevent the laser from effectively ablating the flank face.

[0037] Preferably, in step S2, the flank face of the diamond tool is filled by scanning ablation to form a phase transformation layer on the flank face of the diamond tool, thereby obtaining a diamond tool with a phase transformation layer on the flank face.

[0038] Preferably, the phase change layer includes an amorphous phase change layer and an oriented phase change layer, and the phase change layer in contact with air is the amorphous phase change layer.

[0039] Preferably, the thickness of the amorphous phase transition layer is 0.01~5μm (including but not limited to 0.01μm, 0.1μm, 1μm, 2μm, 5μm), and more preferably 0.05~2μm; the thickness of the orientation phase transition layer is 0.01~2μm (including but not limited to 0.01μm, 0.05μm, 0.1μm, 0.5μm, 1μm, 1.5μm, 2μm), and more preferably 0.1~1μm.

[0040] Preferably, in step S2, the direction of the filling scan is parallel to the cutting edge, and the filling scan starts from the area away from the cutting edge and moves towards the cutting edge, such as... Figure 1 As shown.

[0041] Preferably, the conditions for fill scanning ablation in step S2 are: laser pulse width ≥ 1 ps; spot overlap rate ≥ 90%; laser single pulse energy density * (sinθ)^2 ≥ graphitization threshold of diamond surface. Using these conditions for fill scanning ablation of the flank face of diamond tools helps to form a uniform phase transformation layer on the flank face while significantly reducing thermal damage to the cutting edge.

[0042] This invention achieves precise control over the graphene generation region through laser ablation, enabling direct and accurate graphene formation on the rake face of diamond cutting tools.

[0043] The cutting edge of a diamond tool lies at the junction of its rake and flank faces. Therefore, graphene treatment on the rake face region can significantly increase the risk of damage to the cutting edge, such as from laser ablation and subsequent cleavage. Conventional laser parameter operations can also cause thermal damage to the cutting edge.

[0044] This invention constrains the laser ablation form and parameters, precisely controlling the influence depth and range of the laser-induced phase change layer, reducing damage to the cutting edge. Subsequent annealing removes the amorphous phase change layer, and non-destructive cleavage is performed in a solution, preferably with ultrasonic treatment. This ensures that the remaining orientation phase change layer on the rake face of the diamond tool is cleaved in situ into graphene in a non-contact cleavage form, greatly avoiding damage to the cutting edge.

[0045] Preferably, in step S3, the diamond tool with a phase transformation layer on the back face is annealed to remove the amorphous phase transformation layer, resulting in a diamond tool without an amorphous phase transformation layer on the back face. The annealing process causes the amorphous phase transformation layer to detach, specifically by the gradual oxidation of the amorphous phase transformation layer in air to form carbon dioxide for removal.

[0046] Preferably, the annealing conditions in step S3 are as follows: the annealing temperature is 400~600℃ (including but not limited to 400℃, 450℃, 500℃, 550℃, 600℃), preferably 400~500℃; the annealing time is 2~6h (including but not limited to 2h, 3h, 4h, 5h, 6h), preferably 2~4h; the annealing is carried out in an air atmosphere; and the cooling method is natural cooling in air.

[0047] Preferably, in step S4, the diamond tool without an amorphous phase change layer on the back face is placed in a solution for non-destructive cleavage treatment, so that the remaining orientation phase change layer on the back face is cleaved in situ into graphene, and the tool face is then grapheneized.

[0048] Preferably, the non-destructive cleavage treatment in step S4 includes at least one of ultrasonic treatment, intercalation stripping treatment, and redox treatment.

[0049] Preferably, the solution in step S4 is at least one of N-methylpyrrolidone solution, sodium dodecylbenzenesulfonate solution, and ethanol-propanol mixture; the N-methylpyrrolidone solution is a pure solution (anhydrous); the sodium dodecylbenzenesulfonate solution is an aqueous solution with a concentration of 1~10 mg / ml; the ethanol-propanol mixture is a pure solution, and the ethanol-propanol mixing ratio is preferably 1:1.

[0050] N-methylpyrrolidone solution is preferred.

[0051] Preferably, the non-destructive cleavage treatment in step S4 is ultrasonic treatment. The conditions for ultrasonic treatment are: time 2~6h (including but not limited to 2h, 3h, 4h, 5h, 6h), preferably 4~6h; temperature 40~60℃ (including but not limited to 40℃, 45℃, 50℃, 55℃, 60℃), preferably 45~55℃; power 10~40W (including but not limited to 10W, 15W, 20W, 25W, 30W, 35W, 40W), preferably 20~40W. Treating diamond tools with a phase transformation layer on the flank face using the above conditions is a non-contact treatment method, which can greatly avoid damage to the cutting edge. At the same time, the above treatment method also has good process safety. Contact cleavage inevitably causes mechanical damage to the sharp cutting edge.

[0052] Preferably, in step S4, the angle between the graphene sheet in the graphene and the back face of the diamond tool is independently 30~150° (including but not limited to 30°, 60°, 90°, 120°, 150°), preferably 60~120°; the angle between adjacent single graphene sheets is independently 0~90° (including but not limited to 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°), preferably 0~30°; the height of a single graphene sheet is independently 0.01~2μm, preferably 0.1~1μm, and the lateral dimension is independently 0.01~2μm, preferably 0.1~1μm; the number of layers in a single graphene sheet is independently 1~20 layers (including but not limited to 1 layer, 5 layers, 10 layers, 15 layers, 20 layers), preferably 1~10 layers.

[0053] For sheet-like graphene sheets, the lateral dimension of a single graphene sheet refers to the dimension perpendicular to the thickness direction (such as length, width, and diameter); the number of graphene layers refers to the characteristic in the thickness direction. The size and number of layers of the single graphene sheet in this invention are independently selected from the above-mentioned numerical range. Any two single graphene sheets can be selected, and their size and number of layers can be the same or different.

[0054] The diamond tool parts obtained by the above-mentioned method of maintaining the cutting edge during graphene formation on the flank face include diamond tools with a phase change layer on the flank face obtained in step S2, diamond tools without an amorphous phase change layer on the flank face obtained in step S3, and diamond tools with the oriented phase change layer on the flank face in situ cleaved into graphene obtained in step S4.

[0055] Example 1 A method for maintaining the cutting edge during graphene formation on the flank of a cutting tool includes the following steps: a. Provide diamond cutting tools. Perform ultrasonic cleaning of the diamond cutting tools in anhydrous ethanol for 3 minutes to remove surface oil stains and impurities. Then, clamp them on a rotating platform and adjust the rotation angle so that the back face of the diamond cutting tool is at an angle of 10° with the laser incident direction. b. Using a laser, fill and scan the flank face of the diamond tool from step a) to form a phase transformation layer on the flank face, resulting in a diamond tool with a phase transformation layer on the flank face. Specifically, during laser fill and scan ablation, the fill and scan direction is parallel to the cutting edge, and the scan proceeds from the point furthest from the cutting edge towards the point closer to the cutting edge. Operating parameters include: laser pulse width of 1 ns, wavelength of 355 nm, pulse frequency of 50 kHz, average laser power of 7.6 W, focused spot diameter of 50 μm, and spot overlap rate of 98%. c. Place the diamond tool with the phase transformation layer on the back face in an annealing chamber and perform annealing in an air atmosphere to remove the amorphous phase transformation layer, thus obtaining a diamond tool without the amorphous phase transformation layer on the back face; the annealing operation parameters include: annealing temperature of 500℃, annealing time of 3h, and natural cooling in air. d. Place the diamond tool without an amorphous phase transformation layer on the back face into a solution for ultrasonic treatment, so that the remaining orientation phase transformation layer on the back face is cleaved in situ into graphene. The operating parameters include: the solution is N-methylpyrrolidone solution, the ultrasonic treatment time is 6h, the temperature is 40℃, and the power is 20W.

[0056] Example 2 The difference between this embodiment and Embodiment 1 is that: In step a, adjust the rotation angle so that the back face of the diamond tool is at an angle of 15° to the laser incident direction; In step b, the average laser power is 6.6W; In step c, the annealing temperature is 450℃ and the annealing time is 5h. The ultrasonic treatment time in step d is 4 hours; The rest is the same as in Example 1.

[0057] Example 3 The difference between this embodiment and Embodiment 1 is that: (1) In step a; adjust the rotation angle so that the back face of the diamond tool is at an angle of 15° with the laser incident direction; The average laser power in step b is 6.3W; In step c, the annealing temperature is 400℃ and the annealing time is 6 hours. In step d, the ultrasonic treatment time is 5 hours and the temperature is 50℃. The rest is the same as in Example 1.

[0058] Example 4 The difference between this embodiment and Embodiment 1 is that: In step a, adjust the rotation angle so that the back face of the diamond tool is at an angle of 5° to the laser incident direction; The average laser power in step b is 12W; In step c, the annealing temperature is 450℃ and the annealing time is 4h; In step d, (4) the ultrasonic treatment time is 5 hours; The rest is the same as in Example 1.

[0059] Experimental example: I. Scanning electron microscope image of the diamond tool part in Example 1 is shown below. Figures 2-3 As shown.

[0060] Figure 2 The image shows a scanning electron microscope (SEM) image of the diamond tool with no amorphous phase transition layer on the back face obtained in Example 1. The SEM image shows that the amorphous phase transition layer on the surface has been basically removed, leaving only the orientation phase transition layer.

[0061] Figure 3 The image shows a scanning electron microscope (SEM) image of a diamond tool obtained in Example 1, in which the remaining orientation-state phase change layer on the back face is cleaved into graphene in situ. The SEM image shows that the remaining orientation-state phase change layer is fully cleaved into an in-situ graphene sheet structure.

[0062] II. The cutting edge blunt circle radius diagram of the diamond tool part prepared in Example 1 and the original diamond tool is shown in Figure 1. Figures 4-5 As shown.

[0063] Figure 4 The image shows the cutting edge blunt radius of the diamond tool with the orientation state phase change layer on the flank face in situ cleaved into graphene, prepared in Example 1. Figure 5 This is a diagram showing the blunt radius of the cutting edge of the original diamond tool in Example 1. From... Figure 4 As can be seen from the data, the cutting edge blunt radius of the diamond tool part prepared in Example 1 is 7.0306 μm. Figure 5As can be seen from the original diamond tool part, the cutting edge blunt circle radius is 6.9895μm. The difference between the two is extremely small, which indicates that the present invention has successfully achieved precise graphene formation on the back face of the diamond tool and ensured the sharpness of the diamond tool cutting edge.

[0064] III. The diamond tools with the orientation-state phase change layer on the back face in situ cleaved into graphene prepared in Examples 1-4 were compared with the original diamond tools in a cutting test. The cutting parameters were: cutting speed 150m / min, feed rate 0.1mm / r, depth of cut 0.1mm, machining material 40Cr steel, cutting length 200m. The cutting test data are shown in Table 1.

[0065] Table 1. Comparison of cutting test data between the diamond tools prepared in Examples 1-4 and the original diamond tools.

[0066] Table 1 shows the test results. Compared with the original diamond tool, the diamond tool prepared in Example 1 has a 30% reduction in main cutting force, a flank wear, and a 33% reduction in machined surface roughness, respectively. The diamond tool prepared in Example 2 has a 28% reduction in main cutting force, a flank wear, and a 22% reduction in machined surface roughness, respectively. The diamond tool prepared in Example 3 has a 30% reduction in main cutting force, a flank wear, and a 26% reduction in machined surface roughness, respectively. The diamond tool prepared in Example 4 has a 40% reduction in main cutting force, a flank wear, and a 34% reduction in machined surface roughness, respectively. Examples 1-4 significantly improve the overall cutting performance of the original diamond tool, indicating that the diamond tool prepared in this invention achieves precise grapheneization of the flank while maintaining the sharpness of the cutting edge.

[0067] Fourth, compared with the preparation process of the existing technology, when using the methods and parameters of patent CN117921190A (a method and component for improving the friction reduction and wear resistance of diamond coating) and patent CN112479203A (a method and component for in-situ generation of wear-reducing graphene film on diamond surface) to generate graphene on the back face of diamond tool, it is impossible to maintain the sharpness of the cutting edge, and the cutting edge will chip. It cannot achieve the effect of achieving precise grapheneization on the back face of diamond tool of the present invention while maintaining the sharpness of the cutting edge.

[0068] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for maintaining the cutting edge during graphene formation on the flank of a cutting tool, characterized in that, Includes the following steps: Step S1: Clamp the diamond tool; Step S2: Perform fill scanning ablation on the back face of the diamond tool; Step S3: Anneal the diamond tool obtained in step S2; Step S4: Perform non-destructive cleavage treatment on the diamond tool obtained in step S3, and then graphene-coated the tool surface.

2. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 1, characterized in that, Includes at least one of the following technical features: (1) In step S2, laser is used for filling scanning ablation. The conditions for filling scanning ablation are: the pulse width of the laser is ≥1ps; the spot overlap rate is ≥90%; the laser single pulse energy density*(sinθ)^2 is ≥ the graphitization threshold of the diamond surface; (2) In step S1, the diamond tool is clamped on the rotating platform and the rotation angle is adjusted to adjust the angle between the back face of the diamond tool and the laser incident direction.

3. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 2, characterized in that, Includes at least one of the following technical features: (1) The rotation axis of the rotating platform is perpendicular to the laser incident direction; (2) The angle θ between the back face of the diamond tool and the laser incident direction is 1~20°, preferably 5~15°.

4. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 1, characterized in that, Includes at least one of the following technical features: (1) In step S2, the back face of the diamond tool is filled by scanning ablation to form a phase change layer on the back face of the diamond tool, thereby obtaining a diamond tool with a phase change layer on the back face. (2) In step S2, the direction of the filling scan is parallel to the cutting edge, and the filling scan starts from the distance away from the cutting edge and moves towards the cutting edge.

5. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 4, characterized in that, The phase change layer includes an amorphous phase change layer and an oriented phase change layer, with the amorphous phase change layer being in contact with air.

6. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 5, characterized in that, Includes at least one of the following technical features: (1) The thickness of the amorphous phase change layer is 0.01~5μm, preferably 0.05~2μm; (2) The thickness of the orientation phase change layer is 0.01~2μm, preferably 0.1~1μm.

7. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 5, characterized in that, Includes at least one of the following technical features: (1) In step S3, the diamond tool with phase transformation layer on the back face is annealed to remove the amorphous phase transformation layer and obtain a diamond tool without amorphous phase transformation layer on the back face. (2) The annealing conditions in step S3 are: annealing temperature is 400~600℃, preferably 400~500℃; annealing time is 2~6h, preferably 2~4h; (3) In step S3, the annealing process is carried out in an air atmosphere, and the cooling method is natural cooling in the air; (4) The non-destructive cleavage treatment in step S4 includes at least one of ultrasonic treatment, intercalation stripping treatment, and redox treatment.

8. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 7, characterized in that, Includes at least one of the following technical features: (1) In step S4, the diamond tool without an amorphous phase change layer on the back face is placed in a solution for non-destructive cleavage treatment, so that the orientation phase change layer on the back face is cleaved in situ into graphene, and the back face is then grapheneized. (2) In step S4, the non-destructive cleavage treatment is ultrasonic treatment. The conditions for ultrasonic treatment are: time 2~6h, preferably 4~6h; temperature 40~60℃, preferably 45~55℃; power 10~40W, preferably 20~40W.

9. The method for maintaining the cutting edge during graphene formation on the flank face according to claim 8, characterized in that, Includes at least one of the following technical features: (1) The solution mentioned in step S4 is at least one of N-methylpyrrolidone solution, sodium dodecylbenzenesulfonate solution, and ethanol-propanol mixture; preferably N-methylpyrrolidone solution; (2) In step S4, the angle between the graphene sheet in the graphene and the back face of the diamond tool is independently 30~150°, preferably 60~120°; the angle between adjacent single graphene sheets is independently 0~90°, preferably 0~30°; the height of a single graphene sheet is independently 0.01~2μm, preferably 0.1~1μm, and the lateral dimension is independently 0.01~2μm, preferably 0.1~1μm; The number of layers in a single graphene sheet can be 1 to 20, preferably 1 to 10.

10. A diamond tool part obtained by the method for maintaining the cutting edge during flank graphene formation as described in any one of claims 1 to 9, characterized in that, The diamond tool components include the diamond tool with a phase change layer on the back face obtained in step S2, the diamond tool without an amorphous phase change layer on the back face obtained in step S3, and the diamond tool with the oriented phase change layer on the back face in situ cleaved into graphene obtained in step S4.

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