A method for preparing an ultra-thin high-quality diamond coating of a precision tool
By using a composite dispersant solution and vapor deposition process, the problem of unevenness in ultrathin diamond coatings was solved, resulting in a dense coating on the surface of cemented carbide cutting tools, which improved the tool's service life and performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUBOCK (NINGBO) TECHNOLOGY CO LTD
- Filing Date
- 2026-05-07
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies make it difficult to prepare dense and uniform ultrathin diamond coatings, resulting in uneven coatings and increased thickness, which affects tool quality and lifespan.
Using sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate as a composite dispersant solution, a nanodiamond suspension was prepared by ultrasonic treatment and vapor deposition process, and then uniformly and densely seeded on the surface of cemented carbide cutting tools to form an ultrathin, high-quality diamond coating.
Uniform dispersion of nanodiamonds was achieved, improving the density and uniformity of the ultrathin diamond coating and ensuring the integrity of the tool surface coating and tool life.
Smart Images
Figure CN122279523A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thin film coating modification technology for cemented carbide precision cutting tools, and specifically to a method for preparing an ultra-thin, high-quality diamond coating for precision cutting tools. Background Technology
[0002] For precision cutting tools, diamond coatings are typically 10-20 μm thick, which can affect the precision of the cutting edge. Therefore, ultrathin coatings of 0.2-2 μm thickness are needed to ensure a sharp cutting edge and increase tool hardness, thereby extending tool life. However, during the preparation of ultrathin diamond coatings, incomplete nucleation and failure to grow in some areas can occur, resulting in incomplete coating coverage of the substrate and reduced tool quality. To ensure complete substrate coverage, the preparation time is usually extended, leading to an increase in coating thickness.
[0003] Therefore, the key to preparing ultrathin films lies in the density of the initial nucleation stage, and the crystal implantation process in the pretreatment stage is one of the key reasons for the rapid and dense nucleation in the later stage. Currently, diamond nanoparticles are usually dispersed in anhydrous ethanol, deionized water, or other dispersions to prepare a suspension, and diamond particles are attached to the surface of the cutting tool using ultrasonic equipment for crystal implantation. However, because the nanodiamond particles are prone to agglomeration, it leads to uneven distribution of crystal nuclei and local particle inclusions, resulting in coarse coating grains and non-dense nucleation, making it difficult to prepare ultrathin and dense diamond coating films.
[0004] Therefore, there is an urgent need to develop a surface modification method for cemented carbide precision cutting tools with a dense and uniform ultrathin diamond coating. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an ultra-thin, high-quality diamond coating for precision cutting tools. Using sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate as a composite dispersant solution, it solves the problems of severe clustering and uneven dispersion of nanodiamonds. This promotes uniform and dense seeding of nanodiamonds in the substrate, improving the density and uniformity of the ultra-thin diamond coating on the surface of cemented carbide precision cutting tools. This invention solves the technical problems of unevenness and excessive thickness in existing ultra-thin diamond coatings. To achieve the above technical effects, the following technical solution is adopted: A method for preparing an ultrathin, high-quality diamond coating for precision cutting tools, characterized by comprising the following steps: Step S1: Pre-treat the carbide cutting tool The cemented carbide cutting tool is subjected to etching treatment with alkaline solution and acid solution in sequence to remove the oxide layer, oil and impurities on the substrate surface; Step S2: Preparation of nanodiamond seed solution: Nanodiamond powder was added in batches to a composite dispersant solution while being sonicated. The pH of the system was then adjusted to 9.5-10.5. After ultrasonic dispersion, polyvinylpyrrolidone was added. Large agglomerated particles were removed by centrifugation, and the supernatant was taken to obtain a stable and dispersed nanodiamond suspension. Step S3: Two ultrasonic crystal implantation processes The cutting tip of the cemented carbide tool after the pretreatment in step S1 is placed in the nanodiamond suspension prepared in step S2 for the first ultrasonic crystal implantation. After the crystal implantation is completed, it is cleaned. The first ultrasonic crystal implantation process is repeated for the second ultrasonic crystal implantation, so that the nanodiamond particles are uniformly and densely adsorbed on the substrate surface. Step S4: Perform vapor deposition on the diamond coating An ultrathin diamond coating is deposited on the tool surface using a hot-wire chemical vapor deposition process. Further, step S1 specifically includes: first, immersing the tip of the cemented carbide tool in an alkaline solution, wherein the alkaline solution is prepared by mixing potassium ferricyanide, potassium hydroxide and water in a mass ratio of 0.5~2:1~3:5~20, soaking for 30~60 min, and then rinsing the tip until the rinsing solution is neutral; then immersing the tip of the cemented carbide tool in a mixed oxidizing solution prepared by mixing concentrated sulfuric acid and hydrogen peroxide solution in a volume ratio of 1:0.8~5 for 20~60 s, then rinsing again until the rinsing solution is neutral, and drying for later use; Furthermore, the mass fraction of the hydrogen peroxide solution is 20%~40%; Furthermore, in step S2, the composite dispersant solution is composed of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate in a mass ratio of 1~5:1~3:1~2, and the concentration of the composite dispersant solution is 0.3%~1wt%. Furthermore, in step S2, the particle size of the nanodiamond powder is 100~200 nm, and the amount of nanodiamond powder added is 1.0 wt%~3.0 wt% of the total mass of the composite dispersant solution; Furthermore, in step S2, the centrifugation rate is 5000~8000 r / min, and the centrifugation time is 10~30 min; Furthermore, in step S2, the ultrasonic time when adding nanodiamond powder is 20-40 min and the ultrasonic power is 400-500 W. After adjusting the pH of the system, the ultrasonic time is 15-30 min and the ultrasonic power is 400-500 W. After adding polyvinylpyrrolidone, ultrasonic dispersion is continued for 15-20 min and the ultrasonic power is 400-500 W. Furthermore, in step S3, the first ultrasonic implantation takes 20-40 minutes and the ultrasonic power is 400-500W. The second ultrasonic implantation takes 20-40 minutes and the ultrasonic power is 400-500W. After the first ultrasonic implantation is completed, the crystal is cleaned in anhydrous ethanol solution. Furthermore, in step S4, the reaction gases in the vapor deposition process are hydrogen 1000~2000 sccm, methane 20~100 sccm, and argon 500~1000 sccm, the deposition pressure is 1500~2500 Pa, and the deposition time is 1~3 h; Furthermore, in step S4, the filament diameter is 0.3~0.5 mm, the filament power is 3000 W~7000 W, and the filament spacing is 7~20 mm.
[0006] The beneficial effects of this invention are as follows: This invention provides a method for preparing an ultrathin, high-quality diamond coating for precision cutting tools. Using sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate as a composite dispersant solution, it solves the problem of severe clustering and uneven dispersion of nanodiamonds. The sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate synergistically enhance the dispersion of nanodiamonds in the seed crystal solution, thereby promoting uniform and dense seed crystal formation of nanodiamonds on the substrate, improving the density and uniformity of the ultrathin diamond coating on the surface of cemented carbide precision cutting tools, and solving the technical problems of unevenness and excessive thickness in existing ultrathin diamond coatings. Attached Figure Description
[0007] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0008] Figure 1 This is a SEM image of the ultrathin diamond coating deposited on the surface of the cutting tool in Embodiment 1 of the present invention, wherein... Figure 1 (a) is a SEM image of the coating surface morphology. Figure 1 (b) is a SEM image of the coating cross-sectional thickness; Figure 2 This is a SEM image of the surface morphology of the diamond coating deposited on the tool surface in Comparative Example 1 of the present invention. Figure 3 This is a SEM image of the surface morphology of the diamond coating deposited on the tool surface in Comparative Example 2 of the present invention. Figure 4 This is a SEM image of the surface morphology of the diamond coating deposited on the tool surface in Comparative Example 3 of the present invention. Detailed Implementation
[0009] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0010] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0011] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.
[0012] In the following examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the art; unless otherwise specified, the experimental methods and techniques used are conventional methods and techniques in the art.
[0013] The technical solutions provided by the present invention will be described below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.
[0014] Example 1 Step S1: Pre-treat the carbide cutting tool A two-step alkaline-acid etching process is used to remove the oxide layer, oil, and impurities from the substrate surface. The first step, alkaline washing, involves immersing the carbide cutting tool tip in an alkaline solution (potassium ferricyanide, potassium hydroxide, and water in a mass ratio of 1:1:10) for 45 minutes. The tip is then rinsed three times with deionized water until the rinsing solution is neutral. The second step, acid washing, involves immersing the cutting tool tip in a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 1:1 for 30 seconds. The concentrated sulfuric acid has a mass fraction of 98%, and the hydrogen peroxide solution has a mass fraction of 30%. The tip is then rinsed again with deionized water until neutral and dried with nitrogen gas for later use.
[0015] Step S2: Preparation of nanodiamond seed solution: A composite dispersant solution was prepared, consisting of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate in a mass ratio of 1:1:1, with a concentration of 0.5 wt%. 2.0 wt% of nanodiamond powder with a particle size of 200 nm was added to the dispersant solution in batches, while simultaneously sonicating for 30 min at a power of 400 W. The pH of the system was then adjusted to approximately 10 with dilute sodium hydroxide, followed by sonication for 20 min at a power of 400 W. Next, 0.5% of PVP-K30 was added to the composite dispersant solution and sonicated for 20 min at a power of 400 W to enhance system stability. Finally, the system was centrifuged at 6500 r / min for 20 min to remove large agglomerated particles, and the supernatant was collected to obtain a stable and dispersed nanodiamond suspension.
[0016] Step S3: Two ultrasonic crystal implantation processes The pretreated carbide cutting tool tip was placed in a dispersed nanodiamond suspension and ultrasonically implanted for 30 minutes at an ultrasonic power of 400 W for the first implantation. After the first implantation, it was cleaned in a 99% anhydrous ethanol solution. After cleaning, the first ultrasonic implantation process was repeated for the second ultrasonic implantation, which lasted for 30 minutes at an ultrasonic power of 400 W, so that the nanodiamond particles were uniformly and densely adsorbed on the substrate surface.
[0017] Step S4: Perform vapor deposition on the diamond coating Hot-filament chemical vapor deposition (HFCVD) was used for deposition. The reaction gases were hydrogen (1500 sccm), methane (50 sccm), and argon (800 sccm). The deposition pressure was 2000 Pa, the filament diameter was 0.4 mm, the filament power was 5000 W, the filament spacing was 10 mm, and the deposition time was 2 h. An ultrathin diamond coating with a thickness of approximately 0.7 μm was deposited on the tool surface. Figure 1 This is a SEM image of the ultrathin diamond coating deposited on the surface of the cutting tool in Embodiment 1 of the present invention. Figure 1 It can be seen that the ultrathin diamond coating deposited on the surface of the tool has high density and few internal pores. Figure 1 a) The coating structure is dense and complete ( Figure 1 b).
[0018] Example 2 Step S1: Pre-treat the carbide cutting tool A two-step alkaline-acid etching process is used to remove the oxide layer, oil, and impurities from the substrate surface. The first step, alkaline washing, involves immersing the carbide cutting tool tip in an alkaline solution (potassium ferricyanide, potassium hydroxide, and water in a mass ratio of 2:3:20) for 30 minutes. The tip is then rinsed three times with deionized water until the rinsing solution is neutral. The second step, acid washing, involves immersing the cutting tool tip in a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 1:3 for 40 seconds. The concentrated sulfuric acid has a mass fraction of 98%, and the hydrogen peroxide solution has a mass fraction of 30%. The tip is then rinsed again with deionized water until neutral and dried with nitrogen gas for later use.
[0019] Step S2: Preparation of nanodiamond seed solution: A composite dispersant solution was prepared, consisting of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate in a mass ratio of 3:1:1, with a concentration of 0.5 wt%. 3.0 wt% of the total mass of the composite dispersant solution, containing 180 nm nanodiamond powder, was slowly added to the dispersant solution while simultaneously sonicating for 40 min at a power of 400 W. The pH of the system was then adjusted to approximately 10 using dilute sodium hydroxide, followed by sonication for 30 min at a power of 400 W. Next, 0.5% of the total mass of the composite dispersant solution, containing PVP-K30, was added and sonicated for 20 min at a power of 400 W to enhance system stability. Finally, the system was centrifuged at 8000 r / min for 15 min to remove large agglomerated particles, and the supernatant was collected to obtain a stable and dispersed nanodiamond suspension.
[0020] Step S3: Two ultrasonic crystal implantation processes The pretreated carbide cutting tool tip was placed in a dispersed nanodiamond suspension for ultrasonic implantation. The implantation time was 40 min and the ultrasonic power was 400 W for the first implantation. After the first implantation, the tool tip was cleaned in a 99% anhydrous ethanol solution. After cleaning, the first ultrasonic implantation was repeated for the second ultrasonic implantation process. The second ultrasonic implantation time was 40 min and the ultrasonic power was 400 W, so that the nanodiamond particles were uniformly and densely adsorbed on the substrate surface.
[0021] Step S4: Perform vapor deposition on the diamond coating Hot filament chemical vapor deposition (HFCVD) was used for deposition. The reaction gases were hydrogen 2000 sccm, methane 100 sccm, and argon 1000 sccm. The deposition pressure was 2500 Pa, the filament diameter was 0.5 mm, the filament power was 7000 W, the filament spacing was 20 mm, and the deposition time was 3 h. An ultrathin diamond coating with a thickness of about 1 μm was deposited on the tool surface, which can form a dense ultrathin diamond coating on the tool surface.
[0022] Example 3 Step S1: Pre-treat the carbide cutting tool A two-step alkaline-acid etching process is used to remove the oxide layer, oil, and impurities from the substrate surface. The first step, alkaline washing, involves immersing the carbide cutting tool tip in an alkaline solution (potassium ferricyanide, potassium hydroxide, and water in a mass ratio of 1:1:5) for 30 minutes. The tip is then rinsed three times with deionized water until the rinsing solution is neutral. The second step, acid washing, involves immersing the cutting tool tip in a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 1:0.8 for 20 seconds. The concentrated sulfuric acid has a mass fraction of 98%, and the hydrogen peroxide solution has a mass fraction of 30%. The tip is then rinsed again with deionized water until neutral and dried with nitrogen gas for later use.
[0023] Step S2: Preparation of nanodiamond seed solution: A composite dispersant solution was prepared, consisting of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate in a mass ratio of 1:3:2, with a concentration of 0.5 wt%. 1.0 wt% of the total mass of the composite dispersant solution, containing 180 nm nanodiamond powder, was slowly added to the dispersant solution while simultaneously sonicating for 20 min at a power of 400 W. The pH of the system was then adjusted to approximately 10 with dilute sodium hydroxide, and the mixture was sonicated for 15 min at a power of 400 W. Next, 0.5% of the total mass of the composite dispersant solution, containing PVP-K30, was added and sonicated for 15 min at a power of 400 W to enhance system stability. Finally, the mixture was centrifuged at 5000 r / min for 30 min to remove large agglomerated particles, and the supernatant was collected to obtain a stable and dispersed nanodiamond suspension.
[0024] Step S3: Two ultrasonic crystal implantation processes The pretreated carbide cutting tool tip was placed in a dispersed nanodiamond suspension and ultrasonically implanted for 20 minutes at an ultrasonic power of 400 W for the first implantation. After the first implantation, it was cleaned in a 99% anhydrous ethanol solution. After cleaning, the first ultrasonic implantation process was repeated for the second ultrasonic implantation, with a time of 20 minutes and an ultrasonic power of 400 W, so that the nanodiamond particles were uniformly and densely adsorbed on the substrate surface.
[0025] Step S4: Perform vapor deposition on the diamond coating Hot filament chemical vapor deposition (HFCVD) was used for deposition. The reaction gases were 1000 sccm of hydrogen, 20 sccm of methane, and 500 sccm of argon. The deposition pressure was 1500 Pa, the filament diameter was 0.3 mm, the filament power was 3000 W, the filament spacing was 7 mm, and the deposition time was 1 h. An ultrathin diamond coating with a thickness of approximately 0.5 μm was deposited on the tool surface, which was able to form a dense ultrathin diamond coating on the tool surface.
[0026] Comparative Example 1 Based on Example 1, except that the composite dispersant solution consisted of sodium hexametaphosphate and sodium dodecylbenzenesulfonate in a mass ratio of 1:1 (the total concentration of the composite dispersant solution remained unchanged at 0.5 wt%), all other experimental conditions were the same as in Example 1. The results showed that... Figure 2 It can be seen that the diamond coating has a relatively loose structure and low density, and the overall component distribution of the coating is not uniform, failing to form a continuous and dense film on the tool surface.
[0027] Comparative Example 2 Based on Example 1, except that the composite dispersant solution consisted of sodium hexametaphosphate and sodium polyacrylate in a mass ratio of 1:1 (the total concentration of the composite dispersant solution remained unchanged at 0.5 wt%), all other experimental conditions were the same as in Example 1. The results showed that... Figure 3 It can be seen that the diamond coating has defects such as high porosity and insufficient density, and the surface morphology of the coating is uneven; a continuous and dense film has not been formed on the surface of the tool.
[0028] Comparative Example 3 Based on Example 1, except that the composite dispersant solution consisted of sodium dodecylbenzenesulfonate and sodium polyacrylate in a mass ratio of 1:1 (the total concentration of the composite dispersant solution remained unchanged at 0.5 wt%), all other experimental conditions were the same as in Example 1. The results showed that... Figure 4 It can be seen that the internal structure of the diamond coating is not dense, with many pore defects and uneven distribution of microstructure, and it has failed to form a continuous and dense film on the tool surface.
[0029] Comparative Example 4 Based on Example 1, except that sodium hexametaphosphate solution was used instead of the composite dispersant solution (the total concentration of the sodium hexametaphosphate solution was 0.5 wt%), the other experimental conditions were the same as in Example 1. The results showed that the coating failed to form a continuous and dense film on the tool surface, and the overall coating thickness and component distribution uniformity were poor.
[0030] Comparative Example 5 Based on Example 1, except that sodium dodecylbenzenesulfonate solution was used instead of the composite dispersant solution (the concentration of sodium dodecylbenzenesulfonate solution was 0.5 wt%), all other experimental conditions were the same as in Example 1. The results showed that the coating failed to form a continuous and dense film on the tool surface, and the overall coating thickness and component distribution uniformity were poor.
[0031] Comparative Example 6 Based on Example 1, except that the sodium polyacrylate solution was used instead of the composite dispersant solution (the concentration of the sodium polyacrylate solution was 0.5 wt%), all other experimental conditions were the same as in Example 1. The results showed that the coating failed to form a continuous and dense film on the tool surface, and the overall coating thickness and component distribution uniformity were poor.
[0032] Therefore, those skilled in the art will recognize that although embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.
Claims
1. A method for preparing an ultrathin, high-quality diamond coating for precision cutting tools, characterized in that, Includes the following steps: Step S1: Pre-treat the carbide cutting tool The cemented carbide cutting tool is subjected to etching treatment with alkaline solution and acid solution in sequence to remove the oxide layer, oil and impurities on the substrate surface; Step S2: Preparation of nanodiamond seed solution: Nanodiamond powder was added in batches to a composite dispersant solution while being sonicated. The pH of the system was then adjusted to 9.5-10.
5. After ultrasonic dispersion, polyvinylpyrrolidone was added. Large agglomerated particles were removed by centrifugation, and the supernatant was taken to obtain a stable and dispersed nanodiamond suspension. Step S3: Two ultrasonic crystal implantation processes The cutting tip of the cemented carbide tool after the pretreatment in step S1 is placed in the nanodiamond suspension prepared in step S2 for the first ultrasonic crystal implantation. After the crystal implantation is completed, it is cleaned. The first ultrasonic crystal implantation process is repeated for the second ultrasonic crystal implantation, so that the nanodiamond particles are uniformly and densely adsorbed on the substrate surface. Step S4: Perform vapor deposition on the diamond coating An ultrathin diamond coating is deposited on the tool surface using a hot-wire chemical vapor deposition process.
2. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, Step S1 specifically includes: First, immersing the tip of the cemented carbide tool in an alkaline solution, wherein the alkaline solution is prepared by mixing potassium ferricyanide, potassium hydroxide and water in a mass ratio of 0.5~2:1~3:5~20, soaking for 30~60 min, and then rinsing the tip until the rinsing solution is neutral; then immersing the tip of the cemented carbide tool in a mixed oxidizing solution prepared by mixing concentrated sulfuric acid and hydrogen peroxide solution in a volume ratio of 1:0.8~5 for 20~60 s, and then rinsing again until the rinsing solution is neutral, and drying for later use.
3. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 2, characterized in that, The hydrogen peroxide solution has a mass fraction of 20% to 40%.
4. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S2, the composite dispersant solution is composed of sodium hexametaphosphate, sodium dodecylbenzenesulfonate, and sodium polyacrylate in a mass ratio of 1~5:1~3:1~2, and the concentration of the composite dispersant solution is 0.3%~1wt%.
5. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S2, the particle size of the nanodiamond powder is 100~200 nm, and the amount of nanodiamond powder added is 1.0 wt%~3.0 wt% of the total mass of the composite dispersant solution.
6. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S2, the centrifugation rate is 5000~8000 r / min and the centrifugation time is 10~30 min.
7. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S2, the ultrasonic time when adding nanodiamond powder is 20-40 min and the ultrasonic power is 400-500 W. After adjusting the pH of the system, the ultrasonic time is 15-30 min and the ultrasonic power is 400-500 W. After adding polyvinylpyrrolidone, ultrasonic dispersion is continued for 15-20 min and the ultrasonic power is 400-500 W.
8. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S3, the first ultrasonic implantation takes 20-40 minutes and the ultrasonic power is 400-500 W. The second ultrasonic implantation takes 20-40 minutes and the ultrasonic power is 400-500 W. After the first ultrasonic implantation is completed, the crystal is cleaned in anhydrous ethanol solution.
9. The method for preparing an ultrathin, high-quality diamond coating for a precision cutting tool as described in claim 1, characterized in that, In step S4, the reaction gases in the vapor deposition process are hydrogen (1000-2000 sccm), methane (20-100 sccm), and argon (500-1000 sccm), the deposition pressure is 1500-2500 Pa, and the deposition time is 1-3 h.
10. A method for preparing an ultrathin, high-quality diamond coating for precision cutting tools as described in claims 1-9, characterized in that, In step S4, the filament diameter is 0.3~0.5 mm, the filament power is 3000~7000 W, and the filament spacing is 7~20 mm.