A diamond-coated tool for processing laminated materials and a preparation method thereof

Abstract

The present application relates to the field of diamond tool technology, and specifically discloses a diamond-coated tool for processing laminated materials and a preparation method thereof. The diamond-coated tool for processing laminated materials provided in the present application includes a tool substrate and a diamond coating; the surface roughness of the diamond coating is 0.1-0.3 μm; the diamond coating includes a nucleation layer, a bottom layer, a transition layer and a surface layer; the thickness of the bottom layer is 4-6 μm and the particle size is 3-5 μm; the thickness of the transition layer is 2-3 μm and the particle size is 1-3 μm; the thickness of the surface layer is 1-2 μm and the particle size is 20-100 nm; the present application also provides a preparation method for a diamond-coated tool, including tool substrate pretreatment, seed crystal and hot wire deposition. The diamond-coated tool of the present application has both high wear resistance and low surface roughness. When used for processing laminated materials in the aerospace field, it can achieve good processing accuracy and excellent service life.

Description

Technical Field

[0001] The present application relates to the technical field of diamond cutting tools, and in particular to a diamond-coated cutting tool for processing laminated materials and a preparation method thereof. Background Art

[0002] Laminated materials are a new type of material composed of lightweight metals such as titanium and aluminum, and carbon fiber reinforced composites (CFRPs). CFRPs and metals are both typically difficult to machine, with significantly different physical properties and, consequently, exhibiting significant differences in cutting performance. For example, CFRPs exhibit high hardness, low interlaminar shear strength, and poor thermal conductivity, making them prone to delamination and burning during machining. Light metals such as titanium and aluminum, on the other hand, experience high temperatures during machining, making them prone to deformation, chilling, and tool sticking.

[0003] At present, the main tools used for processing laminated materials on the market are diamond tools, which have characteristics such as high hardness and low roughness, and can effectively solve the delamination and burning problems of carbon fiber reinforced composites. At the same time, relevant research shows that by regulating the crystal morphology of diamond tools, different precision processing requirements can be achieved. For example, diamond tools with stacked spherical or cauliflower-shaped crystals can meet the high-precision and high-finish processing requirements of carbon fiber reinforced composites; diamond tools with tetrahedral micron crystals can meet the wear-resistant processing requirements; however, diamond tools with stacked spherical or cauliflower-shaped crystals have slightly poor wear resistance, and diamond tools with tetrahedral micron crystals have poor processing finish. Therefore, when the above-mentioned diamond tools are used for precision processing of laminated materials, it is impossible to simultaneously take into account the requirements of processing accuracy and tool life, resulting in serious limitations on the application of diamond tools.

[0004] In summary, there is an urgent need to develop a diamond tool that can take into account both machining accuracy and tool life requirements to solve the machining problem of carbon fiber / metal laminates. Summary of the Invention

[0005] In order to solve the problem that it is difficult to simultaneously meet the requirements of both the processing accuracy and tool life of laminated materials in the current industrial production of laminated materials, the present application provides a diamond-coated tool for processing laminated materials and a preparation method thereof.

[0006] In a first aspect, the present application provides a diamond-coated tool for processing laminated materials, which adopts the following technical solution:

[0007] A diamond-coated tool for processing laminated materials, comprising a tool substrate and a diamond coating; the surface roughness of the diamond coating is 0.1-0.3 μm;

[0008] The diamond coating comprises a nucleation layer, a bottom layer, a transition layer and a surface layer; the bottom layer has a thickness of 4-6 μm and a particle size of 3-5 μm; the transition layer has a thickness of 2-3 μm and a particle size of 1-3 μm; the surface layer has a thickness of 1-2 μm and a particle size of 20-100 nm.

[0009] The present application provides a diamond-coated tool, which is composed of a tool substrate and a diamond coating deposited on the surface of the tool substrate. The present application controls the arrangement of diamond crystals and the grain size in the diamond coating under the above conditions, so that the diamond-coated tool obtained can have the characteristics of high wear resistance and low surface roughness. Therefore, the diamond-coated tool produced has excellent processing accuracy and service life. It is used for the processing of laminated materials in the aerospace field and can fully meet the processing requirements of laminated materials.

[0010] In this application, the nucleation layer can fill the pit defects on the surface of the tool substrate, making the surface of the tool substrate uniform and smooth; the bottom layer can increase the adhesion of the diamond coating on the surface of the tool substrate; the transition layer serves as a buffer layer to improve the impact resistance of the diamond-coated tool; the refinement layer is to further fill the residual microscopic defects on the surface of the transition layer and further reduce the surface roughness of the diamond coating.

[0011] Optionally, the tool base satisfies the following conditions: profile arithmetic mean deviation Ra≤0.1 μm, profile maximum height Rz≤1 μm, profile unit average width RSm≤0.05 μm, and cutting edge micro-serrations <1 μm.

[0012] This application can provide excellent deposition conditions for subsequent chemical deposition by quantitatively controlling the original roughness and edge morphology of the tool, thereby improving the processing accuracy of the diamond-coated tool and ensuring the repeatability and stability of the diamond-coated tool in chemical production.

[0013] In a second aspect, the present application provides a method for preparing a diamond-coated cutting tool.

[0014] A method for preparing a diamond-coated cutting tool comprises the following steps: cutting tool substrate pretreatment, seeding, and hot wire deposition; the hot wire deposition comprises surface nucleation, bottom layer deposition, transition layer deposition, and surface layer deposition;

[0015] In the transition layer deposition step, the volume flow rate of methane is 5 to 15 sccm, the volume flow rate of hydrogen is 500 to 1000 sccm, and the volume flow rate of nitrogen is 1000 to 2000 sccm;

[0016] In the surface deposition step, the volume flow rate of methane is 40-60 sccm, the volume flow rate of hydrogen is 500-1000 sccm, and the volume flow rate of nitrogen is 500-1000 sccm;

[0017] During the deposition of the transition layer and the surface layer, a bias voltage of 20-80V is set between the tool base and the hot wire, and the base where the tool base is located is grounded as a negative electrode.

[0018] The present application provides a method for preparing a diamond-coated tool, which adopts a negative bias + high nitrogen low carbon concentration hot wire deposition process. Among them, by forming a certain size of negative bias between the electrode and the tool, the dissociated carbon source group can be promoted to move to the tool substrate, the nucleation rate is improved, the crystal orientation of the deposited diamond particles is more uniform, and it has better impact resistance and wear resistance, thereby improving the service life of the tool. The high nitrogen atmosphere can effectively balance the distribution of plasma groups after thermal dissociation of carbon source particles, increase the collision of carbon source particles and reduce the energy of single cluster diamonds, making the grown diamond particles flatter and denser, while reducing the size of diamond particles without changing the crystal morphology, so that the diamond coating has both high wear resistance and low roughness. And the deposition rate under the high nitrogen low carbon concentration atmosphere is low, which can reduce the stress between crystals during the deposition process and improve the impact resistance of the diamond coating. In addition, the low carbon concentration atmosphere can also avoid the problems of excessive deposition rate and many deposition defects and difficult to accurately control the coating size when depositing diamond coatings with traditional high carbon concentration and low pressure. Therefore, the preparation method of the diamond-coated cutting tool provided in the present application can significantly improve the impact resistance and wear resistance of the diamond-coated cutting tool, thereby increasing the service life of the diamond-coated cutting tool.

[0019] In some embodiments, the bias voltage between the tool substrate and the hot wire can be 20-40V, 20-50V, 20-60V, 40-50V, 40-60V, 40-80V, 50-60V, 50-80V, or 60-80V.

[0020] In a specific embodiment, the bias voltage between the tool substrate and the hot wire can also be 20V, 40V, 50V, 60V or 80V.

[0021] In some embodiments, during the transition layer deposition step, the volume flow rate of nitrogen may be 1000 to 1500 sccm or 1500 to 2000 sccm.

[0022] In a specific embodiment, in the transition layer deposition step, the volume flow rate of nitrogen can be 1000 sccm, 1500 sccm or 2000 sccm.

[0023] In some embodiments, in the surface layer deposition step, the volume flow rate of nitrogen gas may be 500-800 sccm or 800-1000 sccm.

[0024] In a specific embodiment, in the surface layer deposition step, the volume flow rate of nitrogen gas can be 500 sccm, 800 sccm or 1000 sccm.

[0025] Optionally, in the surface nucleation step, the volume flow rate of methane is 10 to 50 sccm, the volume flow rate of hydrogen is 500 to 1000 sccm, and the volume flow rate of nitrogen is 500 to 1000 sccm;

[0026] In the bottom layer deposition step, the volume flow rate of methane is 10-20 sccm, and the volume flow rate of hydrogen is 500-1000 sccm.

[0027] Optionally, the seeding step is specifically as follows: ultrasonically oscillating the pretreated tool substrate in seeding solution I and seeding solution II in sequence, each for 10-30 minutes;

[0028] In the crystal planting solution I, the particle size of the diamond powder is 2-5 μm and the content is 0.1-2 g / 100 mL;

[0029] In the crystal planting solution II, the particle size of the diamond powder is 0.1-0.5 μm and the content is 0.1-2 g / 100 mL.

[0030] Optionally, the solvent in the planting crystal solution I and the planting crystal solution II is acetone, glycerol or ethanol.

[0031] In the seeding step of the present application, the tool substrate is first seeded with a seeding solution I containing larger-sized diamond micropowder, so that the larger-sized diamond micropowder is deposited on the tool surface, providing sites for subsequent diamond crystal growth; then, a seeding solution II containing smaller-sized diamond micropowder is used for seeding, which further improves the uniformity, flatness and density of the growth sites, making the diamond crystals grow more uniformly and densely, thereby ensuring that the obtained diamond coating has lower roughness and better wear resistance.

[0032] Optionally, in the surface nucleation step, the reaction pressure is 1000-2000 Pa, and the deposition time is 0.5-1 h; in the bottom layer deposition step, the reaction pressure is 3500-4500 Pa, and the deposition time is 5-8 h; in the transition layer deposition step, the reaction pressure is 1500-2500 Pa, and the deposition time is 4-6 h; in the surface layer deposition step, the reaction pressure is 500-1000 Pa, and the deposition time is 2-4 h.

[0033] Optionally, the material of the heating wire is one or more of tungsten, tantalum, and rhenium, the heating wire is arranged in a horizontal arrangement, the diameter of the heating wire is 0.5-1 mm, and the spacing between the heating wires is 20-50 mm.

[0034] Optionally, the tool substrate pretreatment includes edge micro-passivation, surface roughening and cobalt removal treatment.

[0035] In the present application, a soft abrasive is first used as a medium to mix diamond micropowder and use a directional jet of air as a medium to impact the surface of an alloy tool, so that the tool base produces a micro-passivation effect on the cutting edge; then, a hard abrasive and refined diamond particles are used as a mixed abrasive, and the tool blade is completely inserted into the mixed abrasive so that the tool and the abrasive rub against each other; finally, the tool surface is treated with a mixed acid solution to reduce the cobalt content on the surface of the cemented carbide tool to 0.2-0.5% by mass.

[0036] Optionally, the soft abrasive is soft rubber particles with a particle size of 0.5-1.5 μm; the diamond micropowder has a specification of 1000-10000 mesh; the hard abrasive is crushed walnut shells or olive shells, and the particle size range after crushing is 1.5-2 mm; the refined diamond particles have a specification of 2000-6000 mesh; and the mixed acid solution is hydrochloric acid and hydrogen peroxide in a volume ratio of 3:(9-12).

[0037] In the present application, a tiny arc can be produced at the cutting edge position of the tool substrate by micro-passivation, which can eliminate the slight sawtooth of the cutting edge that cannot be avoided by tool grinding, thereby reducing the stress concentration of the tool during the cutting process and improving the strength and service life of the tool. Surface roughening treatment can replace traditional alkali corrosion treatment, thereby producing uniform micron-scale scratches on the tool surface, helping to improve the uniformity and uniformity of the initial growth of diamond particles, increasing the surface nucleation rate during the deposition process, avoiding the formation of a loose layer, and thus improving the processing performance and service life of the diamond-coated tool. Cobalt removal treatment can remove Co from the surface of the tool substrate, reduce the diamond to graphite phase transition caused by Co diffusion to the surface of the tool substrate during the deposition process, improve the bonding force between the diamond coating and the tool substrate, and avoid coating shedding.

[0038] In summary, this application has the following beneficial effects:

[0039] 1. This application prepares a diamond-coated tool with high wear resistance and low surface roughness by depositing a layer of diamond coating on the surface of the tool substrate. Using the diamond-coated tool to process laminated materials can avoid the problems of delamination and burning of carbon fiber reinforced composite materials, reduce burning and tool sticking of titanium alloys, and also reduce the number of tool changes and machine downtime, thereby improving processing efficiency and economic benefits.

[0040] 2. This application provides excellent deposition conditions for subsequent chemical deposition by quantitatively controlling the original roughness and edge morphology of the tool, thereby improving the processing accuracy of the diamond-coated tool and ensuring the repeatability and stability of the diamond-coated tool in chemical production.

[0041] 3. In the preparation method of the diamond-coated tool provided in this application, by adopting a negative bias deposition process, the crystal orientation of the diamond particles deposited on the surface of the tool substrate is made more uniform, the impact resistance and wear resistance of the diamond-coated tool are better, and the service life is longer.

[0042] 4. In the preparation method of the diamond-coated cutting tool provided in the present application, by adopting a high nitrogen and low carbon concentration hot wire deposition process, the grown diamond particles can be made smoother and denser, and the obtained diamond-coated cutting tool has higher wear resistance and lower surface roughness, thereby significantly improving the service life of the cutting tool.

[0043] 5. The tool substrate pretreatment process employed in this application combines edge micro-passivation, surface roughening, and cobalt removal. Compared to the acid-base treatments used in related technologies, this process does not affect the tool's original strength and rigidity, achieves more uniform surface roughening, and avoids the generation of toxic and highly polluting wastewater. Therefore, the diamond-coated tool preparation method provided in this application is capable of achieving stable industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a SEM image of the diamond-coated tool provided in Example 3 at 3000 times magnification;

[0045] Figure 2 This is a SEM image of the diamond-coated tool provided in Comparative Example 1 at 3000 times magnification;

[0046] Figure 3 This is a SEM image of the diamond-coated tool provided in Comparative Example 5 at 3000 times magnification;

[0047] Figure 4 is a Raman spectrum of the diamond-coated tool provided in Example 3;

[0048] Figure 5 This is a Raman spectrum of the diamond-coated tool provided in Comparative Example 1. DETAILED DESCRIPTION

[0049] The present application provides a diamond-coated cutting tool, comprising a cutting tool substrate and a diamond coating. The diamond coating has a surface roughness of 0.1-0.3 μm and comprises a nucleation layer, a base layer, a transition layer, and a surface layer. The base layer has a thickness of 4-6 μm and a particle size of 3-5 μm; the transition layer has a thickness of 2-3 μm and a particle size of 1-3 μm; and the surface layer has a thickness of 1-2 μm and a particle size of 20-100 nm. The cutting tool substrate satisfies the following requirements: profile arithmetic mean deviation Ra ≤ 0.1 μm, profile maximum height Rz ≤ 1 μm, profile unit average width RSm ≤ 0.05 μm, and cutting edge micro-serrations < 1 μm.

[0050] The method for preparing the diamond-coated cutting tool comprises the following steps:

[0051] (1) Tool substrate pretreatment:

[0052] (1-1) Prepare a cemented carbide tool substrate and inspect its surface roughness and cutting edge condition under a 100x optical microscope to ensure that it meets the following requirements: profile arithmetic mean deviation Ra ≤ 0.1 μm, profile maximum height Rz ≤ 1 μm, profile unit average width RSm ≤ 0.05 μm, and cutting edge micro-serration < 1 μm.

[0053] (1-2) Micro-passivation of the cutting edge: First, use a fixture to clamp the carbide tool substrate vertically and fix it on the tool disk, select a nozzle diameter of 10-30 mm, adjust the angle between the nozzle and the tool axial direction to 30-45°, and the distance between the nozzle and the tool axis to 30-80 mm; set the sandblasting pressure to 0.1-0.4 MPa, and set the nozzle up and down movement position so that the tool blade can be completely covered; start the sandblasting equipment, and use a mixture of soft rubber particles with a particle size of 0.1-1.5 μm and diamond micropowder with a mesh size of 1000-10000 as the medium. It is sucked in through the compressed air pipe and sprayed from the nozzle onto the rotating tool surface. The sandblasting time is 2-10 minutes.

[0054] (1-3) Surface roughening: Wipe the surface of the carbide milling cutter after sandblasting with ethanol. Then, clamp the carbide milling cutter on the tool tray and place the tool end downward. Lower the tool so that the cutting edge is completely immersed in a mixed abrasive of hard abrasive (crushed walnut shells or olive shells) with a particle size of 1.5-2 mm and fine diamond particles of 2000-6000 mesh. Start the roughening equipment to control the motor that drives the tool to rotate. Set the relative speed of the tool and abrasive to 30-50 r / min and the processing time to 5-30 min. Then, remove the tool, ultrasonically clean it in an acetone solution, and take it out for drying.

[0055] (1-4) Cobalt removal treatment: The carbide tool after the hard abrasive roughening treatment is placed in a mixed acid solution of hydrochloric acid and hydrogen peroxide with a volume ratio of 3: (9-12) and etched for 2-5 minutes to reduce the cobalt content on the surface of the carbide tool to 0.2-0.5% by mass; the tool is then removed and cleaned in anhydrous ethanol and acetone respectively, and then taken out and dried.

[0056] (2) Seeding: The carbide tool obtained by the decobaltization treatment is immersed in the seeding solution I and ultrasonically vibrated for 10-30 minutes; then immersed in the seeding solution II and ultrasonically vibrated for 10-30 minutes; in the seeding solution I, the particle size of the diamond micropowder is 2-5μm and the content is 0.1-2g / 100mL; in the seeding solution II, the particle size of the diamond micropowder is 0.1-0.5μm and the content is 0.1-2g / 100mL.

[0057] (3) Hot wire deposition: Place the carbide tool after seeding into the HFCVD equipment chamber.

[0058] (3-1) Surface nucleation: methane, hydrogen, and nitrogen are introduced into the HFCVD apparatus; wherein the volume flow rate of methane is 10-50 sccm, the volume flow rate of hydrogen is 500-1000 sccm, and the volume flow rate of nitrogen is 500-1000 sccm; the reaction pressure is 1000-2000 Pa; and the surface nucleation is carried out for 0.5-1 h;

[0059] (3-2) Bottom layer deposition: methane and hydrogen are then introduced into the HFCVD apparatus; wherein, the volume flow rate of methane is 10-20 sccm, the volume flow rate of hydrogen is 500-1000 sccm, the reaction pressure is 3500-4500 Pa, and the deposition time is 5-8 h; (3-3) Transition layer deposition: methane, hydrogen, and nitrogen are then introduced into the HFCVD apparatus; wherein, the volume flow rate of methane is 5-15 sccm, the volume flow rate of hydrogen is 500-1000 sccm, the volume flow rate of nitrogen is 1000-2000 sccm, the reaction pressure is 1500-2500 Pa, and the deposition time is 4-6 h;

[0060] (3-4) Surface deposition: The volume flow rate of methane, hydrogen, and nitrogen is adjusted to 40-60 sccm, 500-1000 sccm, and 500-1000 sccm, respectively. The reaction pressure is 500-1000 Pa, and the deposition time is 2-4 h. After the deposition is completed, a diamond-coated tool is obtained.

[0061] In the above processes (3-3) to (3-4), a bias voltage of 20-80V is set between the tool base and the hot wire, and the base where the tool base is located is grounded as the negative pole.

[0062] In this application, raw materials, reagents, solvents, etc. can all be obtained commercially.

[0063] The present application is further described in detail below with reference to the embodiments, performance testing and accompanying drawings.

[0064] Example 1

[0065] Example 1 provides a diamond-coated cutting tool.

[0066] In the above-mentioned diamond-coated tool, the bottom layer has a thickness of 4 μm and a particle size of diamond particles of 3-4 μm; the transition layer has a thickness of 3 μm and a particle size of diamond particles of 1-2 μm; the surface layer has a thickness of 3 μm and a particle size of diamond particles of 20-50 nm.

[0067] The method for preparing the diamond-coated cutting tool comprises the following steps:

[0068] (1) Tool substrate pretreatment:

[0069] (1-1) A cemented carbide tool substrate (a round shank cemented carbide milling cutter made of K05, with a blade diameter of 4 mm, a blade length of 20 mm, a total length of 60 mm, and a shank diameter of 6 mm) was prepared, and its surface roughness and edge condition were tested under a 100x optical microscope. The results showed that the profile arithmetic mean deviation Ra was 0.06 μm, the maximum profile height Rz was 0.8 μm, the average width RSm of the profile unit was 0.04 μm, and the micro-serration of the cutting edge was less than 1 μm.

[0070] (1-2) Micro-passivation of the cutting edge: First, use a fixture to clamp the carbide tool substrate vertically and fix it on the tool disk, select a nozzle diameter of 20 mm, adjust the angle between the nozzle and the tool axial direction to 40°, and the distance between the nozzle and the tool axis is 50 mm; set the sandblasting pressure to 0.2 MPa, and set the nozzle up and down movement position so that the tool edge can be completely covered; start the sandblasting equipment, and use a mixture of soft rubber particles with a particle size of 0.5 μm and 5000 mesh diamond powder as the medium. It is sucked in through the compressed air pipe and sprayed from the nozzle onto the rotating tool surface. The sandblasting time is 5 minutes.

[0071] (1-3) Surface roughening: The surface of the carbide milling cutter after sandblasting was wiped with ethanol. The carbide milling cutter was then clamped on a tool tray with the tool end facing downward. The tool was lowered so that the cutting edge was completely immersed in a mixed abrasive of walnut shells with a particle size of 1.5 to 2 mm and walnut shells and 3000 mesh fine diamond particles. The roughening equipment was started to control the motor that drives the tool to rotate. The relative speed of the tool and the abrasive was set to 45 r / min, and the processing time was 10 min. The tool was then removed and ultrasonically cleaned in an acetone solution, and then removed and dried.

[0072] (1-4) Cobalt removal treatment: The carbide tool after the hard abrasive roughening treatment was placed in a mixed acid solution of hydrochloric acid and hydrogen peroxide with a volume ratio of 3:10 for 2 minutes, and the cobalt content on the surface of the carbide tool was 0.4% by mass. The tool was then taken out and cleaned in anhydrous ethanol and acetone respectively, and then taken out and dried.

[0073] (2) Seeding: The carbide tool obtained by decobaltization treatment was immersed in seeding solution I (acetone solution containing 1 g / 100 mL, 3 μm diamond powder) and ultrasonically vibrated for 20 min; then immersed in seeding solution II (acetone solution containing 1 g / 100 mL, 0.3 μm diamond powder) and ultrasonically vibrated for 20 min.

[0074] (3) Hot wire deposition: Place the carbide tool after seeding into the HFCVD equipment chamber.

[0075] (3-1) Surface nucleation: methane, hydrogen, and nitrogen were introduced into the HFCVD apparatus; the volume flow rate of methane was 30 sccm, the volume flow rate of hydrogen was 1000 sccm, and the volume flow rate of nitrogen was 1000 sccm. The reaction pressure was 2000 Pa, and the surface nucleation was carried out for 0.5 h.

[0076] (3-2) Bottom layer deposition: Methane and hydrogen were then introduced into the HFCVD apparatus. The methane volume flow rate was 20 sccm, the hydrogen volume flow rate was 1000 sccm, the reaction pressure was 4000 Pa, and the deposition time was 6 h.

[0077] (3-3) Transition layer deposition: methane, hydrogen, and nitrogen were introduced into the HFCVD apparatus. The methane volume flow rate was 5 sccm, the hydrogen volume flow rate was 500 sccm, and the nitrogen volume flow rate was 2000 sccm. The reaction pressure was 2000 Pa, and the deposition time was 5 h.

[0078] (3-4) Surface deposition: The volume flow rate of methane was adjusted to 50 sccm, the volume flow rate of hydrogen was adjusted to 500 sccm, the volume flow rate of nitrogen was adjusted to 1000 sccm, the reaction pressure was adjusted to 1000 Pa, and the deposition time was adjusted to 3 h. After the deposition was completed, a diamond-coated tool was obtained.

[0079] In the above processes (3-3) to (3-4), a bias voltage of 20V is set between the tool base and the hot wire, and the base where the tool base is located is grounded as a negative pole.

[0080] Examples 2-5

[0081] Examples 2-5 each provide a diamond-coated cutting tool.

[0082] The difference between the above embodiment and embodiment 1 is that the bias voltage between the tool substrate and the hot wire in the diamond coating tool preparation method is shown in Table 1 below.

[0083] Table 1 Bias voltage between tool substrate and hot wire in the diamond coating tool preparation method provided in Examples 1-5

[0084] Example Bias voltage between tool base and hot wire / V 1 20 2 40 3 50 4 60 5 80

[0085] Examples 6-9

[0086] Examples 6-9 each provide a diamond-coated cutting tool.

[0087] The difference between the above embodiment and embodiment 3 is that the volume flow rate of nitrogen in the transition layer deposition and surface layer deposition steps is shown in Table 2 below.

[0088] Table 2 Volume flow rate of nitrogen in the transition layer deposition and surface layer deposition steps of Example 3, Examples 6-9

[0089]

[0090]

[0091] Example 10

[0092] Example 10 provides a diamond-coated cutting tool.

[0093] The difference between the above embodiment and embodiment 3 lies in the crystal seeding step. The crystal seeding step of embodiment 10 is as follows:

[0094] (2) Seeding: The pretreated carbide tool was immersed in an acetone solution containing 1 g / 100 mL, 3 μm diamond powder and ultrasonically vibrated for 20 min.

[0095] Comparative Example 1

[0096] Comparative Example 1 provides a diamond-coated cutting tool.

[0097] The difference between the comparative example and Example 1 is that in the method for preparing the diamond-coated tool, the bias voltage between the tool substrate and the hot wire is 0.

[0098] Comparative Example 2

[0099] Comparative Example 2 provides a diamond-coated cutting tool.

[0100] The difference between the comparative example and Example 1 is that the bias voltage between the tool substrate and the hot wire in the diamond coating tool preparation method is 100V.

[0101] Comparative Example 3

[0102] Comparative Example 3 provides a diamond-coated cutting tool.

[0103] The difference between the comparative example and Example 1 is that the volume flow rate of nitrogen in the transition layer deposition step is 0.

[0104] Comparative Example 4

[0105] Comparative Example 4 provides a diamond-coated cutting tool.

[0106] The difference between the comparative example and Example 1 is that the volume flow rate of nitrogen in the surface deposition step is 0.

[0107] Comparative Example 5

[0108] Comparative Example 5 provides a diamond-coated cutting tool.

[0109] The difference between the comparative example and Example 1 is that the diamond coating of the diamond-coated cutting tool only includes a nucleation layer, a bottom layer and a transition layer.

[0110] Surface performance testing

[0111] The surface properties of the diamond coating of the diamond-coated tool obtained in Example 3 were tested, and the results are shown in Table 3 below.

[0112] (1) SEM detection: EmCrafts CUBE-ⅡPlus electron microscope energy spectrum integrated machine was used to detect the diamond coating tools obtained in Example 3, Comparative Example 1 and Comparative Example 5. The 3000x SEM image of Example 3 is as follows: Figure 1 As shown, the 3000 times SEM picture of comparative example 1 is as follows Figure 2 As shown, the 3000 times SEM picture of comparative example 5 is as follows Figure 3 shown.

[0113] Depend on Figure 1 It can be seen that the grain orientation of the diamond coating surface of Example 3 is very obvious and relatively uniform, all of which are fine-grained 111 crystal planes, and the surface is dense, without obvious pores, and has good continuity and density. Therefore, the above diamond coating has good wear resistance, adhesion and impact resistance.

[0114] Depend on Figure 2 It can be seen that the crystal phase orientation of the diamond coating surface in Comparative Example 1 is not uniform, and the grains are quite different.

[0115] Depend on Figure 3 It can be seen that the crystal phase orientation of the diamond coating surface in Comparative Example 5 is relatively uniform, but the grains are still quite different.

[0116] (2) Raman spectroscopy: The diamond-coated cutting tools obtained in Example 3 and Comparative Example 1 were subjected to Raman spectroscopy. The results of Example 3 are as follows: Figure 4 As shown, the results of Comparative Example 1 are as follows Figure 5 shown.

[0117] Depend on Figure 4The graph shows a high-intensity diamond peak and a low-intensity nanometer peak, indicating that the diamond coating of Example 3 of the present application has relatively small particles and a partial graphite structure. The graphite structure can improve the lubricity of the coating, thereby reducing the surface roughness of the diamond tool and the cutting heat during machining, thereby achieving a smooth machined surface.

[0118] Depend on Figure 5 It can be seen that there is only one high-intensity diamond peak in the figure, which indicates that the diamond coating of Comparative Example 1 has a high purity and is composed entirely of diamond particles.

[0119] Use performance testing

[0120] The performance of the diamond-coated cutting tools obtained in Examples 1-10 and Comparative Examples 1-5 was tested, and the results are shown in Table 3 below.

[0121] (1) Surface roughness: The surface of the diamond-coated tool was inspected using a KLA nanometer optical profiler to obtain the surface roughness.

[0122] (2) Machining wear test: The machining performance of the diamond-coated tool was tested. The test machine model was DMU70V, the machining parameters were ae=3mm, ap=10mm, the rotation speed was 4800r / min, and the feed was 1600mm / min. The machining material was a laminated material, and the continuous cutting time was 45m. The cutting edge wear was then checked using a Keyence tool 3D profile measuring instrument.

[0123] The laminated material consists of 1 layer of T800 carbon fiber composite material (thickness 10 mm) and 1 layer of Ti6Al4V titanium alloy (thickness 4 mm).

[0124] (3) Service life test: Referring to the test conditions in (1) processing test, the diamond coated tool is used to continuously cut the laminated material to test the length of the laminated material that the diamond coated tool can continuously cut.

[0125] (4) Processing effect: Referring to the test conditions in the processing test, the diamond-coated tool was used to continuously cut the laminated material for 10 m. The T800 carbon fiber fiber layer in the laminated material was observed to see if there were burrs at the boundary, if there was delamination between the layers, and if there was burning during continuous processing. The titanium alloy layer was observed to see if there were burn marks, whether the cutting was smooth, and whether there was any knife sticking.

[0126] Table 3 Performance test results of the milling cutters obtained in Examples 1-10 and Comparative Examples 1-5

[0127]

[0128]

[0129] According to the test results in Table 3, the surface roughness of the diamond-coated cutting tools obtained in Examples 1-10 of the present application is 0.1-0.3 μm, and the wear after cutting 45 m of laminated material is only 0.148-0.228 mm, and the laminated material does not have burrs, delamination, burning and other problems, and the titanium alloy layer does not have burns or knife sticking. The service life of cutting laminated materials using the above-mentioned diamond-coated cutting tools is as long as 60-95 m. The surface roughness of the diamond-coated cutting tool in Comparative Example 5 is as high as 0.66 μm, and it can only cut 18 m of laminated material, and the laminated material after cutting has obvious burrs and delamination. Therefore, it is shown that the preparation method provided by the present application can prepare diamond-coated cutting tools with excellent surface roughness and wear resistance. Using it to process laminated materials can avoid problems such as burrs, delamination, burning and other problems of laminated materials, and can also achieve a longer service life.

[0130] The test results of Examples 1-5 and Comparative Examples 1-2 show that the surface roughness, machining accuracy, and service life of the diamond-coated cutting tools obtained in Examples 1-5 are significantly better than those in Comparative Examples 1-2. This indicates that the method for preparing the diamond-coated cutting tools provided in this application, by providing a bias voltage of 20-80V between the cutting tool substrate and the hot wire, can improve the uniformity of the crystal orientation of the diamond particles, thereby significantly improving the impact resistance and wear resistance of the diamond-coated cutting tools, thereby greatly extending the service life of the diamond-coated cutting tools.

[0131] The test results of Example 3, Examples 6-9, and Comparative Examples 3-4 show that the surface roughness, machining accuracy, and service life of the diamond-coated cutting tools obtained in Example 1 and Examples 6-9 are significantly better than those of Comparative Examples 3-4. This indicates that the preparation method of the diamond-coated cutting tools provided in this application, which uses a high nitrogen and low carbon concentration atmosphere deposition process, can improve the wear resistance of the diamond coating, reduce surface roughness, and thereby extend the service life of the diamond-coated cutting tools.

[0132] The test results of Example 3 and Example 10 show that Example 10 uses only one seeding solution for seeding, and the surface roughness of the diamond-coated tool obtained is 0.17μm, and the wear amount after cutting the laminated material for 45m is 0.228mm, while Example 3 uses two seeding solutions for treatment in sequence, and the surface roughness of the diamond-coated tool obtained is only 0.11μm, and the wear amount after cutting the laminated material for 45m is 0.14mm. Therefore, it is explained that the use of two seeding solutions for seeding in this application can ensure the uniformity of the seeding on the surface of the tool substrate, thereby reducing the surface roughness of the deposited diamond coating, improving the wear resistance of the diamond coating, and extending the service life of the diamond-coated tool.

[0133] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A diamond-coated tool for processing laminated materials, characterized in that: It comprises a tool substrate and a diamond coating; the surface roughness of the diamond coating is 0.1-0.3 μm; The diamond coating comprises a nucleation layer, a bottom layer, a transition layer and a surface layer; the bottom layer has a thickness of 4-6 μm and a particle size of 3-5 μm; the transition layer has a thickness of 2-3 μm and a particle size of 1-3 μm; the surface layer has a thickness of 1-2 μm and a particle size of 20-100 nm; The diamond coating tool is prepared by a method comprising the following steps: tool substrate pretreatment, seeding and hot wire deposition; the hot wire deposition comprises surface nucleation, bottom layer deposition, transition layer deposition and surface layer deposition; In the transition layer deposition step, the volume flow rate of methane is 5-15 sccm, the volume flow rate of hydrogen is 500-1000 sccm, and the volume flow rate of nitrogen is 1000-2000 sccm; In the surface deposition step, the volume flow rate of methane is 40-60 sccm, the volume flow rate of hydrogen is 500-1000 sccm, and the volume flow rate of nitrogen is 500-1000 sccm; During the deposition of the transition layer and the surface layer, a bias voltage of 20-80V is set between the tool base and the hot wire, and the base where the tool base is located is grounded as a negative electrode.

2. The diamond-coated tool according to claim 1, characterized in that The tool base meets the following requirements: profile arithmetic mean deviation Ra≤0.1 μm, profile maximum height Rz≤1 μm, profile unit average width RSm≤0.05 μm, and cutting edge micro-serrations <1 μm.

3. The diamond-coated tool according to claim 1, characterized in that In the surface nucleation step, the volume flow rate of methane is 10-50 sccm, the volume flow rate of hydrogen is 500-1000 sccm, and the volume flow rate of nitrogen is 500-1000 sccm; In the bottom layer deposition step, the volume flow rate of methane is 10-20 sccm, and the volume flow rate of hydrogen is 500-1000 sccm.

4. The diamond-coated tool according to claim 1, characterized in that The seeding step is specifically as follows: ultrasonically oscillating the pretreated tool substrate in seeding solution I and seeding solution II in sequence, each for 10-30 minutes; In the crystal planting solution I, the particle size of the diamond powder is 2-5 μm and the content is 0.1-2 g / 100 mL; In the crystal planting solution II, the particle size of the diamond powder is 0.1-0.5 μm and the content is 0.1-2 g / 100 mL.

5. The diamond-coated tool according to claim 4, characterized in that The solvent in the crystal planting solution I and the crystal planting solution II is acetone, glycerol or ethanol.

6. The diamond-coated tool according to claim 1, characterized in that In the surface nucleation step, the reaction pressure is 1000-2000 Pa and the deposition time is 0.5-1 h; In the bottom layer deposition step, the reaction pressure is 3500-4500 Pa and the deposition time is 5-8 hours; In the transition layer deposition step, the reaction pressure is 1500-2500 Pa and the deposition time is 4-6 hours; In the surface deposition step, the reaction pressure is 500-1000 Pa and the deposition time is 2-4 hours.

7. The diamond-coated tool according to claim 1, characterized in that The material of the heating wire is one or more of tungsten, tantalum, and rhenium. The heating wire is arranged in a horizontal wire arrangement. The diameter of the heating wire is 0.5-1 mm, and the spacing between the heating wires is 20-50 mm.

8. The diamond-coated tool according to any one of claims 1 to 7, characterized in that: The tool matrix pretreatment includes edge micro-passivation, surface roughening and cobalt removal treatment.

9. The diamond-coated tool according to claim 8, characterized in that The cobalt content on the surface of the tool substrate after the cobalt removal treatment is 0.2-0.5%.

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