Manufacturing method of DLC coating milling cutter

Abstract

The invention provides a method for manufacturing a milling cutter with a DLC (diamond-like carbon) coating, which comprises the following four steps: gradient pretreatment of a matrix, deposition of a composite coating, targeted cryogenic post-treatment and precise finishing detection, and is characterized in that gradient strengthening of quenching-tempering-cryogenic pretreatment is carried out on a WC-Co hard alloy matrix, and a gradient component DLC coating is deposited by adopting a PECVD (plasma enhanced chemical vapor deposition) and IBAD composite process; the carbon bond hybridization state is regulated and controlled by matching with-140 DEG C targeted cryogenic aftertreatment, finally, the microhardness of the milling cutter coating reaches 28-32 GPa, the friction coefficient is reduced to 0.08-0.12, the critical load of the film-substrate binding force is larger than or equal to 60 N, and the service life is prolonged by 2-3 times compared with a traditional DLC coating milling cutter under the working condition of high-speed cutting of aluminum alloy and titanium alloy.

Description

Technical Field

[0001] This invention relates to the field of CNC tool manufacturing and surface coating technology, specifically to a method for manufacturing a DLC-coated milling cutter. Background Technology

[0002] DLC (diamond-like carbon) coating, with its high hardness, low coefficient of friction, and excellent wear and corrosion resistance, has become one of the core technologies for improving the performance of CNC milling cutters. As the requirements for cutting accuracy, efficiency, and tool life continue to increase in high-end manufacturing, the application scenarios for DLC-coated milling cutters are expanding. However, existing manufacturing processes still face many technical bottlenecks.

[0003] Traditional DLC-coated end mills often employ a single PVD or CVD process for coating deposition, which suffers from insufficient film-substrate adhesion, excessive internal stress in the coating leading to cracking, and a tendency for coating peeling and cutting edge chipping under high-speed intermittent cutting conditions. Furthermore, existing processes struggle to balance coating hardness and toughness; prioritizing high hardness increases coating brittleness, while emphasizing toughness reduces hardness and wear resistance. In addition, the high-temperature deposition or post-treatment methods used in some processes negatively impact the properties of the WC-Co cemented carbide substrate, further limiting the overall service life of the end mill.

[0004] In existing technologies, cryogenic treatment has been proven to optimize the structure and performance of DLC coatings by improving hardness and adhesion through the control of carbon bond hybridization. However, traditional cryogenic processes use coarse parameters, often employing liquid nitrogen cryogenic treatment at -196℃, which can easily lead to stress mismatch between the coating and the substrate, and it does not achieve synergistic optimization with the coating deposition process. Meanwhile, although gradient coating and composite deposition processes have made some progress, improvements are still needed in areas such as compositional gradient control and transition layer compatibility, failing to fully realize the performance potential of DLC coatings. Therefore, developing a manufacturing process for DLC-coated milling cutters that combines high film-substrate adhesion, high hardness, and low internal stress has become a pressing technical problem for the industry. Summary of the Invention

[0005] To address the problems of insufficient film-substrate adhesion, excessive internal stress, and poor performance synergy in existing DLC-coated end mill manufacturing processes, this invention provides a method for manufacturing high-performance DLC-coated end mills. Through the synergistic design of substrate gradient pretreatment, composite coating deposition, and targeted cryogenic post-treatment, an optimal balance of coating hardness, toughness, and adhesion is achieved, significantly improving the end mill's service life and stability under high-speed cutting conditions. In view of the shortcomings of the existing technology described above,

[0006] To achieve the above objectives, the present invention provides a method for manufacturing a DLC-coated milling cutter, the specific steps of which are as follows:

[0007] Substrate gradient pretreatment: A WC-Co cemented carbide end mill substrate was selected and subjected to quenching, tempering, cryogenic pretreatment, and surface activation treatment in sequence. The quenching temperature was 1420℃~1520℃, held for 1.5h~3.5h, and then cooled to room temperature. The tempering was carried out in two stages: the first stage was held at 190℃~230℃ for 2.5h~4.5h, and the second stage was held at 480℃~530℃ for 1.5h~3h, and then cooled to room temperature. The cryogenic pretreatment temperature was -130℃~-150℃, held for 24h~36h, and then naturally heated to room temperature. The surface activation treatment used plasma cleaning to remove oxides and contaminants from the substrate surface and improve surface activity.

[0008] Composite coating deposition: The pretreated milling cutter substrate is placed in a composite deposition equipment. A transition layer is deposited first, followed by a DLC gradient coating. The transition layer is a metal / metal nitride alternating stacked structure, prepared by magnetron sputtering at a deposition temperature of 170℃~210℃. The DLC gradient coating uses carbon-containing gas as the carbon source, and the performance can be controlled by selecting doping sources. The gas source ratio is dynamically adjusted during the deposition process to make the coating composition gradually distributed. Ion beam assisted deposition is used to improve the coating density. The total coating thickness is 1.2μm~3.5μm, and the deposition temperature is ≤230℃.

[0009] Targeted cryogenic post-treatment: The milling cutter with the deposited coating is placed in a cryogenic treatment device and cooled to the target cryogenic temperature at a rate of 4℃ / min~9℃ / min, held for 24h~36h, and then heated to room temperature at a rate of 1.5℃ / min~3.5℃ / min.

[0010] Precision dressing and inspection: The cutting edge of the milling cutter is precisely dressed to ensure that the cutting edge radius and surface roughness meet the requirements of high-precision cutting; qualified products are screened through hardness testing, adhesion testing, and friction performance testing.

[0011] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the cryogenic pretreatment temperature is -140℃, the heat preservation time is 30h, and magnetic field interference is avoided throughout the process; the argon flow rate for surface activation treatment is 20-30sccm, the vacuum degree is 0.5-1Pa, and the treatment time is 15-20min.

[0012] According to a specific embodiment, in the DLC-coated end mill manufacturing method provided by the present invention, the Co content in the WC-Co cemented carbide matrix is ​​6-8wt%, the average WC particle size is 0.4-0.8μm, the surface hardness of the matrix after gradient pretreatment is ≥1800HV, and the core toughness is ≥15J / cm²; the quenching is carried out by oil cooling, and the tempering is carried out by air cooling.

[0013] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the transition layer is a Cr / CrN alternating stacked structure, with a Cr layer thickness of 50-80nm, a CrN layer thickness of 80-120nm, and 3-5 alternating stacks, and a magnetron sputtering target power of 1.2-1.5kW; the transition layer may also be a Ti / TiN alternating stacked structure.

[0014] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the composite coating deposition adopts a PECVD-IBAD composite process, the carbon-containing gas is a mixture of methane and acetylene, and the dopant source is silane; during the deposition process, the volume ratio of methane to acetylene increases from 1:2 to 2:1, and the silane flow rate decreases from 10 sccm to 2 sccm; the IBAD energy is controlled at 80-100 eV, and the beam current density is 0.8-1.2 mA / cm².

[0015] According to a specific embodiment, in the DLC-coated end mill manufacturing method provided by the present invention, during the composite coating deposition process, the basic pressure inside the vacuum chamber is ≤5×10⁻⁻⁻⁴. 4 Pa, working pressure maintained at 1-3 Pa, bias voltage controlled at -50~-80V, deposition temperature ≤220℃.

[0016] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the target temperature of the targeted cryogenic post-treatment is -140℃, and the temperature is held for 30 hours; the cooling rate is 5-8℃ / min, and the heating rate is 2-3℃ / min; the entire process maintains a vacuum environment with a vacuum degree ≥1×10⁻³Pa.

[0017] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, after the targeted deep cryogenic post-treatment, the sp³ / sp² bond ratio in the DLC coating is ≥0.52, and the residual compressive stress is controlled at -1.2~-0.8GPa, effectively suppressing crack propagation.

[0018] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the precision finishing adopts a combination of chemical mechanical polishing and laser micro-trimming. The polishing fluid is an alkaline colloidal silica polishing fluid, and the laser power is controlled at 5-10W. After finishing, the cutting edge radius is controlled at 0.01-0.03mm, and the surface roughness Ra≤0.2μm.

[0019] According to a specific embodiment, in the DLC-coated milling cutter manufacturing method provided by the present invention, the hardness is tested by nano-indentation method to measure the coating hardness; the adhesion is tested by scratch test to measure film-substrate adhesion; and the friction performance is tested by ball-disc friction test to measure the coefficient of friction.

[0020] Compared with the prior art, the present invention has the following significant advantages:

[0021] The DLC-coated milling cutter manufacturing method provided by this invention solves the problem of balancing hardness and toughness, as well as adhesion and wear resistance, in traditional processes through the synergistic design of substrate gradient pretreatment, PECVD-IBAD composite deposition, and targeted cryogenic post-treatment. Testing shows that the coating microhardness reaches 28-32 GPa, the coefficient of friction is 0.08-0.12, the critical load for film-substrate adhesion is ≥60 N, the sp³ / sp² bond ratio is ≥0.52, and the residual compressive stress is stable at -1.2 to -0.8 GPa. Its crack resistance and density far exceed those of traditional processes. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0023] Example 1

[0024] This embodiment provides a manufacturing process for a high-performance DLC-coated end mill, the specific steps of which are as follows:

[0025] 1. Matrix gradient pretreatment: Select WC-7wt%Co cemented carbide end mill matrix (WC average grain size 0.6μm), quench at 1480℃ for 2.5h, and oil cool to room temperature; first stage tempering at 210℃ for 3.5h, second stage tempering at 510℃ for 2.2h, and air cool to room temperature; -140℃ cryogenic holding for 30h, and natural heating to room temperature; plasma cleaning (argon flow rate 25sccm, vacuum degree 0.8Pa, treatment for 18min).

[0026] 2. Composite Coating Deposition: In the PECVD-IBAD composite equipment, a Cr / CrN transition layer (60 nm Cr layer, 100 nm CrN layer, alternating in 4 groups) was deposited by magnetron sputtering at a target power of 1.3 kW and a deposition temperature of 190 °C. A DLC gradient coating was then deposited, with the methane to acetylene volume ratio increased from 1:2 to 2:1, the silane flow rate decreased from 10 sccm to 2 sccm, the IBAD energy was 90 eV, the beam current density was 1.0 mA / cm², the deposition temperature was 200 °C, and the vacuum base pressure was 3 × 10⁻⁻⁻⁻⁶. 4 Pa, working pressure 2Pa, bias voltage -65V, total coating thickness 2.2μm.

[0027] 3. Targeted cryogenic post-treatment: In a vacuum cryogenic equipment, the temperature is lowered to -140℃ at a rate of 5℃ / min, held for 30 hours, and then raised to room temperature at a rate of 2℃ / min, with a vacuum degree of 2×10⁻³Pa.

[0028] 4. Precision finishing and testing: Chemical mechanical polishing with alkaline colloidal silica polishing slurry, micro-trimming with laser power of 8W, cutting edge radius of 0.02mm, surface roughness Ra=0.15μm; the coating hardness was tested to be 30.2GPa, friction coefficient of 0.10, critical load of film-substrate adhesion of 63N, sp³ / sp² bond ratio of 0.55, and residual compressive stress of -1.0GPa.

[0029] The milling cutter of this embodiment was used for high-speed milling of aluminum alloy battery trays for new energy vehicles (cutting speed 300m / min, feed rate 0.2mm / r), with a service life of 220 hours, which is 1.6 times longer than that of traditional DLC coated milling cutters (85 hours). The surface roughness Ra is ≤0.2μm, which meets the requirements of precision machining.

[0030] Example 2

[0031] This embodiment provides a manufacturing process for a DLC-coated end mill adapted for cutting titanium alloys, the steps of which are as follows:

[0032] 1. Matrix gradient pretreatment: WC-8wt%Co cemented carbide matrix (WC average particle size 0.4μm), quenched at 1500℃ for 2h, oil cooled; tempered at 220℃ for 3h, tempered at 520℃ for 2h; cryogenically cooled at -140℃ for 30h; plasma cleaning (argon gas 30sccm, vacuum degree 1Pa, treatment for 20min).

[0033] 2. Composite coating deposition: Cr / CrN transition layer (Cr layer 80nm, CrN layer 120nm, alternating 5 groups), target power 1.5kW, deposition temperature 200℃; DLC gradient coating methane / acetylene ratio 1:2 to 2:1, silane 10-2sccm, IBAD energy 100eV, beam current density 1.2mA / cm², deposition temperature 220℃, working pressure 3Pa, bias voltage -80V, coating thickness 3μm.

[0034] 3. Targeted cryogenic post-treatment: Cool down to -140℃ at 8℃ / min, hold for 30h, heat up to room temperature at 3℃ / min, vacuum degree 1×10⁻³Pa.

[0035] 4. Finishing and inspection: Cutting edge radius 0.03mm, Ra=0.18μm; coating hardness 31.5GPa, friction coefficient 0.09, critical load of bonding force 65N, used for milling titanium alloy TC4 (cutting speed 80m / min), life reaches 90 minutes, which is 1.6 times better than traditional DLC end mills (35 minutes).

[0036] Example 3

[0037] This embodiment provides a manufacturing process for DLC-coated end mills using a Ti / TiN transition layer, suitable for cutting carbon fiber reinforced polymer (CFRP) and aluminum alloy composite components. The steps are as follows:

[0038] 1. Matrix gradient pretreatment: Select WC-6wt%Co cemented carbide end mill matrix (WC average grain size 0.8μm), quench at 1450℃ for 3h, and oil cool to room temperature; first stage tempering at 190℃ for 4.5h, second stage tempering at 490℃ for 2.8h, and air cool to room temperature; -140℃ cryogenic holding for 30h, and natural heating to room temperature (no magnetic field interference throughout the process); plasma cleaning (argon flow rate 22sccm, vacuum degree 0.6Pa, treatment for 16min).

[0039] 2. Composite Coating Deposition: In the PECVD-IBAD composite equipment, a Ti / TiN transition layer (75 nm Ti layer, 110 nm TiN layer, alternating in 4 groups) was deposited by magnetron sputtering. The Ti target power was 1.4 kW, and the deposition temperature was 190 °C. A DLC gradient coating was then deposited, with the methane to acetylene volume ratio increased from 1:2 to 2:1, the silane flow rate decreased from 10 sccm to 2 sccm, the IBAD energy was 95 eV, the beam current density was 1.1 mA / cm², the deposition temperature was 210 °C, and the vacuum base pressure was 4 × 10⁻⁻⁻⁻⁶. 4 Pa, working pressure 2.2Pa, bias voltage -70V, total coating thickness 2.5μm.

[0040] 3. Targeted cryogenic post-treatment: In a vacuum cryogenic equipment, the temperature is lowered to -140℃ at 6℃ / min, held for 30h, and then raised to room temperature at 2.5℃ / min, with a vacuum degree of 1.5×10⁻³Pa.

[0041] 4. Precision finishing and testing: Chemical mechanical polishing with alkaline colloidal silica polishing slurry, micro-trimming with laser power of 7W, cutting edge radius of 0.025mm, surface roughness Ra=0.16μm; the coating hardness was tested to be 29.8GPa, friction coefficient of 0.11, critical load of film-substrate adhesion of 62N, sp³ / sp² bond ratio of 0.54, residual compressive stress of -0.9GPa, and coating density of 95%.

[0042] The milling cutter of this embodiment was used for milling CFRP-aluminum alloy composite components (cutting speed 250m / min, feed rate 0.18mm / r), with a service life of 185 hours. During the cutting process, there was no coating peeling, the cutting edge wear was uniform, and there were no burrs on the interface of the composite material after machining. The surface roughness of the aluminum alloy Ra=0.18μm. Compared with the milling cutter with Cr / CrN transition layer (service life of 160 hours under the same working conditions), it has better corrosion resistance and is suitable for humid cutting environments.

[0043] Comparison table of transition layer performance between Example 1 and Example 3

[0044] Transition layer type Single-group layer thickness parameters Magnetron sputtering parameters Coating hardness coefficient of friction Critical load of membrane-substrate bonding force Cr / CrN Cr layer 60nm, CrN layer 100nm Cr target, power 1.3kW, deposition temperature 190℃ 30.2 GPa 0.10 63 N Ti / TiN Ti layer 75nm, TiN layer 110nm Ti target, power 1.4kW, deposition temperature 190℃ 29.8 GPa 0.11 62 N

[0045] As shown in the table above, both transition layers can meet the core usage requirements of high-performance DLC-coated end mills, forming differentiated adaptation advantages: the Cr / CrN system is superior in hardness and friction performance, and is suitable for high-speed dry cutting conditions to pursue ultimate cutting efficiency; the Ti / TiN system has better interfacial compatibility and corrosion resistance, and is more stable in composite component processing and humid cutting environments, which confirms the flexibility and process adaptability of the transition layer selection of this invention.

[0046] Comparative Example 1

[0047] A DLC coating was deposited using a conventional PECVD process. The substrate underwent only quenching and tempering treatment, without cryogenic pretreatment or post-treatment. Other parameters were consistent with those in Example 1. The coating was found to have a hardness of 25.3 GPa, a coefficient of friction of 0.16, a critical load of 42 N for film-substrate adhesion, a sp³ / sp² bond ratio of 0.38, and a residual compressive stress of -0.5 GPa. When used for milling aluminum alloy battery trays, the coating had a service life of only 85 hours. Significant coating peeling occurred after 60 hours of cutting, and the surface roughness increased to 0.35 μm.

[0048] Comparative Example 2

[0049] The same substrate pretreatment (including cryogenic pretreatment), composite coating deposition, and finishing process as in Example 1 was used, except that the targeted cryogenic post-treatment was replaced with traditional -196℃ liquid nitrogen cryogenic treatment (holding at this temperature for 24 hours, without controlled temperature rise and fall, in an atmospheric environment). The coating hardness was measured to be 27.8 GPa, the coefficient of friction to be 0.13, the critical load for film-substrate adhesion to be 51 N, the sp³ / sp² bond ratio to be 0.45, and the residual compressive stress to be -1.8 GPa (prone to cracking). When used for milling aluminum alloy battery trays, the service life was 132 hours. Two microcracks appeared on the cutting edge coating during the cutting process, resulting in a 40% reduction in service life compared to Example 1.

[0050] Comparative Example 3

[0051] A DLC coating was deposited using a single PECVD process (without IBAD assistance or gradient component control). The substrate underwent the gradient pretreatment described in Example 1, followed by the targeted cryogenic post-treatment and finishing process of this invention. The coating hardness was measured to be 26.5 GPa, the coefficient of friction to be 0.14, the critical load for film-substrate adhesion to be 48 N, and the coating density to be 89% (compared to 96% in Example 1). When used for milling aluminum alloy battery trays, the coating lifespan was 156 hours. Due to insufficient coating density, significant abrasive wear occurred during cutting, resulting in a 29% reduction in lifespan compared to Example 1.

[0052] The above embodiments and comparative embodiments demonstrate that the present invention, through the synergistic design of "gradient pretreatment + PECVD-IBAD composite deposition + targeted cryogenic post-treatment," significantly outperforms traditional processes in terms of hardness, adhesion, friction performance, and service life. Each core step is indispensable: targeted cryogenic temperature and rate control strategies prevent stress cracking; IBAD assistance and compositional gradients improve coating density; and gradient pretreatment strengthens substrate support. The performance advantages of this process have been verified through multivariate comparisons, demonstrating clear and stable technical effects and possessing significant technical advantages and industrial application value.

Claims

1. A method for manufacturing a DLC-coated milling cutter, characterized in that, Includes the following steps: Substrate gradient pretreatment: A WC-Co cemented carbide end mill substrate was selected and subjected to quenching, tempering, cryogenic pretreatment, and surface activation treatment in sequence. The quenching temperature was 1420℃~1520℃, held for 1.5h~3.5h, and then cooled to room temperature. The tempering was carried out in two stages: the first stage was held at 190℃~230℃ for 2.5h~4.5h, and the second stage was held at 480℃~530℃ for 1.5h~3h, and then cooled to room temperature. The cryogenic pretreatment temperature was -130℃~-150℃, held for 24h~36h, and then naturally heated to room temperature. The surface activation treatment used plasma cleaning to remove oxides and contaminants from the substrate surface and improve surface activity. Composite coating deposition: The pretreated milling cutter substrate is placed in a composite deposition equipment, where a transition layer is deposited first, followed by the deposition of a DLC gradient coating; The transition layer is a metal / metal nitride alternating stacked structure, prepared by magnetron sputtering at a deposition temperature of 170℃~210℃; the DLC gradient coating uses carbon-containing gas as the carbon source, and the performance can be controlled by selecting doping sources. The gas source ratio is dynamically adjusted during the deposition process to make the coating composition gradually distributed. Ion beam assisted deposition process is used to improve the coating density. The total coating thickness is 1.2μm~3.5μm, and the deposition temperature is ≤230℃. Targeted cryogenic post-treatment: The milling cutter with the deposited coating is placed in a cryogenic treatment device and cooled to the target cryogenic temperature at a rate of 4℃ / min~9℃ / min, held for 24h~36h, and then heated to room temperature at a rate of 1.5℃ / min~3.5℃ / min. Precision dressing and inspection: The cutting edge of the milling cutter is precisely dressed so that the cutting edge radius and surface roughness meet the requirements of high-precision cutting; Qualified products are selected through hardness testing, bonding strength testing, and friction performance testing.

2. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The cryogenic pretreatment temperature is -140℃, and the temperature is maintained for 30 hours, avoiding magnetic field interference throughout the process; the argon flow rate for surface activation treatment is 20-30 sccm, the vacuum degree is 0.5-1 Pa, and the treatment time is 15-20 min.

3. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The WC-Co cemented carbide matrix has a Co content of 6-8wt%, an average WC particle size of 0.4-0.8μm, and a surface hardness ≥1800HV and a core toughness ≥15J / cm² after gradient pretreatment. The quenching is performed by oil cooling and the tempering is performed by air cooling.

4. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The transition layer is a Cr / CrN alternating stacked structure, with a Cr layer thickness of 50-80 nm and a CrN layer thickness of 80-120 nm, and 3-5 alternating stacks, with a magnetron sputtering target power of 1.2-1.5 kW; the transition layer can also be a Ti / TiN alternating stacked structure.

5. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The composite coating deposition adopts the PECVD-IBAD composite process, the carbon-containing gas is a mixture of methane and acetylene, and the dopant source is silane; during the deposition process, the volume ratio of methane to acetylene increases from 1:2 to 2:1, and the silane flow rate decreases from 10 sccm to 2 sccm; the IBAD energy is controlled at 80-100 eV, and the beam current density is 0.8-1.2 mA / cm².

6. The method for manufacturing a DLC-coated milling cutter according to claim 1 or 5, characterized in that, During the deposition of the composite coating, the basic pressure inside the vacuum chamber is ≤5×10⁻ 4 Pa, working pressure maintained at 1-3 Pa, bias voltage controlled at -50~-80V, deposition temperature ≤220℃.

7. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The target temperature for the targeted cryogenic post-treatment is -140℃, and the temperature is maintained for 30 hours; the cooling rate is 5-8℃ / min, and the heating rate is 2-3℃ / min; the entire process maintains a vacuum environment with a vacuum degree ≥1×10⁻³Pa.

8. The method for manufacturing a DLC-coated milling cutter according to claim 1 or 7, characterized in that, After the targeted cryogenic post-treatment, the sp³ / sp² bond ratio in the DLC coating is ≥0.52, and the residual compressive stress is controlled at -1.2~-0.8GPa, effectively suppressing crack propagation.

9. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The precision finishing process employs a combination of chemical mechanical polishing and laser micro-trimming. The polishing fluid is an alkaline colloidal silica polishing fluid, and the laser power is controlled at 5-10W. After finishing, the cutting edge radius is controlled at 0.01-0.03mm, and the surface roughness Ra≤0.2μm.

10. The method for manufacturing a DLC-coated milling cutter according to claim 1, characterized in that, The hardness test uses the nanoindentation method to measure the coating hardness; the adhesion test uses the scratch test to measure the film-substrate adhesion; and the friction performance test uses the ball-disc friction test to measure the coefficient of friction.