High-hardness coating method

Abstract

The invention discloses a high-hardness film coating method, and relates to the technical field of film coating. The invention relates to a high-hardness coating method, which comprises the following steps of: preparing, etching, depositing a Cr film, depositing a first CrSiCN film, depositing a CrSiN film, depositing a second CrSiCN film, cooling after coating, and taking out a workpiece. The application has the effects of improving the Moh's hardness of the film coating and improving the adhesive force of the straight part of the edge of the coating.

Description

Technical Field

[0001] The invention relates to the technical field of film coating, and in particular to a high-hardness film coating method. Background Art

[0002] Magnetron sputtering coating refers to a coating technology that uses the coating material as the target cathode, bombards the target material with argon ions, generates cathode sputtering, and sputters the target material particles onto the workpiece to form a deposited layer. The principle is that the plasma generated by the abnormal glow discharge of argon gas bombards the surface of the target cathode under the action of the electric field, and the molecules, atoms, ions and electrons on the surface of the target cathode are sputtered out with a certain kinetic energy. The particles are ejected toward the surface of the workpiece in a certain direction, thereby forming a coating on the surface of the workpiece.

[0003] Magnetron sputtering coating is the most widely used sputtering deposition method, which is applied to the fields of optics, materials, semiconductors, electronics, etc. By coating a conductive film layer on the surface of glass, sapphire or ceramics, the comprehensive properties of the workpiece, such as hardness, corrosion resistance, and wear resistance, can be improved, and the service life of the workpiece can be increased. Among them, the most common binary film is CrN coating. The bonding force between the binary film and the workpiece is not strong. Si and C elements are often doped in the CrN-based coating to improve the high-temperature oxidation resistance, wear resistance and water lubrication performance of the CrN-based coating.

[0004] The commonly used coating method in the market is through magnetron sputtering revolution. The workpiece rotates along the axis of the coating chamber. At this time, the Mohs hardness of the coating is low, and the adhesion of the edge of the coating is poor, which affects the use effect of the coating. Summary of the invention

[0005] In order to improve the Mohs hardness of the coating and improve the adhesion of the edge of the coating, the present application provides a high-hardness coating method.

[0006] A high hardness coating method provided in this application adopts the following technical solution: A high hardness coating method comprises the following steps: (1) Preparation: Install Cr target and Cr / Si mixed target in magnetron sputtering coating equipment, clean the workpiece by ultrasonic, dry it and fix it on the rotating rack of the coating chamber of magnetron sputtering coating equipment, evacuate the coating chamber and preheat the workpiece, and start the rotating rack to rotate; (2) Etching: introduce argon gas into the coating chamber with a flow rate of 30-40 sccm, use ion beam to etch the workpiece, and the etching time is 4-5 minutes; (3) Deposition of Cr film: Continue to introduce argon gas into the coating chamber, increase the argon gas flow rate to 170-190sccm, set the Cr target current to 18-20A, start deposition, and the deposition time is 5-7min; (4) Deposition of the first CrSiCN film: Keep argon gas flowing, and introduce nitrogen and acetylene into the coating chamber at the same time, heat the coating chamber to 180-210°C, keep warm for 30-40 minutes, then turn off the heating, start heat preservation coating, set the Cr / Si target current to 15-16A, and the deposition time to 30-32 minutes; (5) Deposition of CrSiN film: Keep argon gas flowing, turn off acetylene, increase nitrogen flow, set Cr / Si target current to 18-20A, start deposition, deposition time 10-12min; (6) Deposition of the second CrSiCN film: Keep argon gas flowing, introduce acetylene, reduce nitrogen flow, heat the coating chamber to 180-210°C, keep warm for 30-40 minutes, then turn off the heating, start heat preservation coating, set the Cr / Si target current to 12-13A, and the deposition time to 35-38 minutes; (7) After coating, cool down and remove the workpiece.

[0007] By adopting the above technical solution, the coating is a laminated structure of Cr / first CrSiCN / CrSiN / second CrSiCN. The Cr film is used as a base, which has strong interface fusion performance and can achieve high bonding strength between the film and the workpiece; the CrSiCN film can greatly reduce the friction coefficient of the film by doping Si and C elements, and hinder the generation and diffusion of cracks through the solid solution of Si and C, refine the grains, and thus improve the hardness of the film; adding a CrSiN transition layer between the two CrSiCN films can prevent the propagation of tiny cracks inside the lattice and reduce the adverse effect of the increase of free C on the hardness of the film. The prepared film has a smooth and dense surface and has excellent hardness, wear resistance and corrosion resistance.

[0008] When depositing the CrSiCN film, the temperature during coating can be kept constant by heat-insulating the coating. According to the ideal gas state equation PV=nRT, the gas pressure and volume are inversely proportional at this time. The film defects caused by the heating temperature can be reduced during coating, and the film will not have pinhole light transmission phenomenon, thereby improving the reliability of the film.

[0009] Optionally, the nitrogen flow rate in step (4) and step (6) is 120-125 sccm, and the acetylene flow rate is 30-40 sccm.

[0010] By adopting the above technical solution, the flow ratio of argon, nitrogen and acetylene is controlled, the phase structure of the film is controlled, the crystallinity of the film is improved, Si and C form solid solutions respectively, and the volume fractions of amorphous Si3N4 and free C are reduced.

[0011] Optionally, the nitrogen flow rate in step (5) is 160-165 sccm.

[0012] By adopting the above technical solution, the flow rate of nitrogen is increased, so that nitrogen can be combined with Cr to form a stable crystal phase, which is convenient for deposition to form a CrSiN film.

[0013] Optionally, the ion source voltage in step (2) is 1100-1300V.

[0014] By adopting the above technical solution, the ion source voltage is controlled to emit an ion beam, and the surface of the workpiece can be cleaned by the ion beam, the pollutants on the surface can be removed, and the optical and electrical properties of the workpiece surface can be changed.

[0015] Optionally, the mixing ratio of the Cr / Si mixed target in step (1) is Cr:Si=9:1.

[0016] By adopting the above technical solution, the doping amount of Si is controlled to avoid the volume fraction of amorphous Si3N4 being too high, which affects the crystallinity and hardness of the film.

[0017] Optionally, the thickness of each layer of the thin film is: 100-110 nm for the Cr film, 60-70 nm for the first CrSiCN film, 140-150 nm for the CrSiN film, and 200-210 nm for the second CrSiCN film.

[0018] By adopting the above technical solution, the thickness ratio of each layer of the film is controlled, so that the bonding force between the layers of the film is strong and the comprehensive performance is good.

[0019] Optionally, the purity of the Cr target in step (1) is 99.5% or above; and the rotation speed of the turntable is 25-30 r / min.

[0020] By adopting the above technical solution, the speed of the rotating frame is controlled, so that the coating rate is high and the uniformity of the coating is good.

[0021] Optionally, the coating temperature of step (2), step (3) and step (5) is set at 100-180°C.

[0022] By adopting the above technical solution, the coating temperature is controlled, thereby facilitating the control of the sputtering rate of the target material and the diffusion rate during the deposition process, so that the film has good adhesion and hardness.

[0023] Optionally, the magnetron sputtering coating equipment includes a coating chamber, a rotating rack for placing workpieces is provided in the coating chamber, the rotating rack is connected to a reciprocating fixture, the rotating rack is connected to a bias power supply, and a target material and a four-way gas flow control system are provided in the coating chamber.

[0024] By adopting the above technical solution, the front and back surfaces and the vertical position can be coated at one time through the orbital and self-rotating fixture, which solves the risk of film adhesion in the vertical position and improves the coating efficiency.

[0025] Optionally, the bias power supply in step (2) is set to -800 V, the bias power supply in step (3) is set to -80 V, the bias power supply in steps (4) and (6) is set to -120 V, and the bias power supply in step (5) is set to -150 V.

[0026] In summary, this application has the following beneficial effects: 1. The coating is a laminated structure of Cr / first CrSiCN / CrSiN / second CrSiCN. The Cr film is used as a base, which has strong interface fusion performance and can achieve high bonding strength between the film and the workpiece. The CrSiCN film can greatly reduce the friction coefficient of the film by doping Si and C elements. The solid solution of Si and C hinders the generation and diffusion of cracks, refines the grains, and thus improves the hardness of the film. Adding a CrSiN transition layer between the two CrSiCN films can prevent the propagation of tiny cracks inside the lattice and reduce the adverse effect of the increase of free C on the hardness of the film. The prepared film has a smooth and dense surface and has excellent hardness, wear resistance and corrosion resistance.

[0027] When depositing the CrSiCN film, the temperature during coating can be kept constant by heat-insulating the coating. According to the ideal gas state equation PV=nRT, the gas pressure and volume are inversely proportional at this time. The film defects caused by the heating temperature can be reduced during coating, and the film will not have pinhole light transmission phenomenon, thereby improving the reliability of the film.

[0028] 2. The front and back surfaces and the vertical position can be coated at one time through the revolving fixture, which solves the risk of film adhesion in the vertical position and improves the coating efficiency. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with Examples 1-3 and Comparative Examples 1-3. Example

[0030] The magnetron sputtering coating equipment is used in the coating process. The magnetron sputtering coating equipment used in the present application includes a coating chamber, a rotating frame is provided in the coating chamber, the rotating frame is used to place the workpiece, the rotating frame is connected to a revolving fixture, and the revolving fixture can drive the rotating frame to revolve and rotate. The rotating frame is connected to a bias power supply, and the bias power supply can apply a negative bias to the workpiece. The coating chamber is also provided with a target material and a four-way gas flow control system. In the present application, the gas flow ratio of argon, nitrogen and acetylene in the coating chamber is controlled by a flow meter.

[0031] Example 1 A high hardness coating method comprises the following steps: (1) Preparation: Install a Cr target and a Cr / Si mixed target in a magnetron sputtering coating device, wherein the purity of the Cr target is 99.5% or above, and the mixing ratio of the Cr / Si mixed target is Cr:Si=9:1; The workpiece was ultrasonically cleaned, and the workpiece was placed in acetone, ethanol and deionized water for 15 minutes in turn. After drying, it was fixed on the rotating rack of the coating chamber of the magnetron sputtering coating equipment, the coating chamber was evacuated, the workpiece was preheated to 80°C, and the rotating rack was turned on at a rotating speed of 25r / min; (2) Etching: The coating chamber is evacuated to 2×10-2Pa, the heating system is turned on and the temperature is raised to 100°C, argon gas is introduced into the coating chamber, the argon content is 30sccm, the bias power supply sets the workpiece bias to -800V, the ion source voltage is set to 1100V, and the Ar+ ion beam generated by the ion source is accelerated to bombard the workpiece surface for 4 minutes to remove pollutants on the workpiece surface and activate the deposition surface; (3) Deposition of Cr film: Continue to introduce argon gas into the coating chamber, increase the argon gas flow rate to 170 sccm, maintain the temperature at 100°C, set the workpiece bias voltage to -80V, the Cr target current to 18A, and start depositing the Cr film for 5 minutes; (4) Deposition of the first CrSiCN film: Keep argon gas flowing, and introduce nitrogen and acetylene into the coating chamber at the same time, where the nitrogen flow rate is 120 sccm and the acetylene flow rate is 30 sccm. Heat the coating chamber to 180°C, keep it warm for 30 minutes, turn off the baking heating, and keep the workpiece warm in a hollow environment for coating. Set the workpiece bias to -120V for the bias power supply, the Cr / Si target current to 15A, and the deposition time to 30 minutes; (5) Deposition of CrSiN film: Keep argon gas flowing, turn off acetylene, increase nitrogen flow rate to 160sccm, lower the temperature in the coating chamber to 100°C, set the workpiece bias voltage of the bias power supply to -150V, set the Cr / Si target current to 18A, start deposition, and the deposition time is 10min; (6) Deposition of the second CrSiCN film: Keep argon gas flowing, introduce acetylene into the coating chamber, reduce nitrogen flow, maintain nitrogen flow at 120sccm, acetylene flow at 30sccm, heat the coating chamber to 180°C, keep warm for 30min, turn off baking heating, keep the workpiece warm in a hollow environment, set the bias voltage of the workpiece to -120V, the Cr / Si target current to 12A, start deposition, and the deposition time is 35min; (7) After coating, cool down and remove the workpiece.

[0032] The thickness of each layer of the obtained thin film is: 100nm for the Cr film, 60nm for the first CrSiCN film, 140nm for the CrSiN film, and 200nm for the second CrSiCN film.

[0033] Example 2 A high hardness coating method comprises the following steps: (1) Preparation: Install a Cr target and a Cr / Si mixed target in a magnetron sputtering coating device, wherein the purity of the Cr target is 99.5% or above, and the mixing ratio of the Cr / Si mixed target is Cr:Si=9:1; The workpiece was ultrasonically cleaned, and the workpiece was placed in acetone, ethanol and deionized water for washing for 20 minutes in turn. After drying, the workpiece was fixed on the rotating rack of the coating chamber of the magnetron sputtering coating equipment, the coating chamber was evacuated, the workpiece was preheated to 100°C, and the rotating rack was turned on at a rotating speed of 30r / min; (2) Etching: The coating chamber is evacuated to 6×10-2Pa, the heating system is turned on and the temperature is raised to 180°C, argon gas is introduced into the coating chamber, the argon content is 40sccm, the bias power supply sets the workpiece bias to -800V, the ion source voltage is set to 1300V, and the Ar+ ion beam generated by the ion source is accelerated to bombard the workpiece surface for 4 minutes to remove pollutants on the workpiece surface and activate the deposition surface; (3) Deposition of Cr film: Continue to introduce argon gas into the coating chamber, increase the argon gas flow rate to 190 sccm, maintain the temperature at 180°C, set the workpiece bias voltage to -80V, the Cr target current to 20A, and start depositing the Cr film for 7 minutes; (4) Deposition of the first CrSiCN film: Keep argon gas flowing, and introduce nitrogen and acetylene into the coating chamber at the same time, where the nitrogen flow rate is 125 sccm and the acetylene flow rate is 40 sccm. Heat the coating chamber to 210°C, keep it warm for 40 minutes, turn off the baking heating, and keep the workpiece warm in a hollow environment for coating. Set the workpiece bias to -120V for the bias power supply, the Cr / Si target current to 16A, and the deposition time to 32 minutes; (5) Deposition of CrSiN film: Keep argon gas flowing, turn off acetylene, increase nitrogen flow rate to 165sccm, reduce the temperature in the coating chamber to 180°C, set the workpiece bias voltage to -150V, the Cr / Si target current to 20A, start deposition, and the deposition time is 12min; (6) Deposition of the second CrSiCN film: Keep argon gas flowing, introduce acetylene into the coating chamber, reduce nitrogen flow, maintain nitrogen flow at 125sccm, acetylene flow at 40sccm, heat the coating chamber to 210°C, keep warm for 40min, turn off baking heating, keep the workpiece warm in a hollow environment, set the bias voltage of the workpiece to -120V, set the Cr / Si target current to 13A, start deposition, and the deposition time is 38min; (7) After coating, cool down and remove the workpiece.

[0034] The thickness of each layer of the obtained thin film is: 110nm for the Cr film, 70nm for the first CrSiCN film, 150nm for the CrSiN film, and 210nm for the second CrSiCN film.

[0035] Example 3 A high hardness coating method comprises the following steps: (1) Preparation: Install a Cr target and a Cr / Si mixed target in a magnetron sputtering coating device, wherein the purity of the Cr target is 99.5% or above, and the mixing ratio of the Cr / Si mixed target is Cr:Si=9:1; The workpiece was ultrasonically cleaned, and the workpiece was placed in acetone, ethanol and deionized water for 18 minutes in turn. After drying, the workpiece was fixed on the rotating rack of the coating chamber of the magnetron sputtering coating equipment, the coating chamber was evacuated, the workpiece was preheated to 90°C, and the rotating rack was turned on at a rotating speed of 30r / min; (2) Etching: The coating chamber is evacuated to 4×10-2Pa, the heating system is turned on and the temperature is raised to 150℃, argon gas is introduced into the coating chamber, the argon content is 35sccm, the bias power supply sets the workpiece bias to -800V, the ion source voltage is set to 1200V, and the Ar+ ion beam generated by the ion source is accelerated to bombard the workpiece surface for 5min to remove pollutants on the workpiece surface and activate the deposition surface; (3) Deposition of Cr film: Continue to introduce argon gas into the coating chamber, increase the argon gas flow rate to 180 sccm, maintain the temperature at 150°C, set the workpiece bias voltage of the bias power supply to -80V, the Cr target current to 20A, and start depositing the Cr film for 5 minutes; (4) Deposition of the first CrSiCN film: Keep argon flowing, and introduce nitrogen and acetylene into the coating chamber at the same time, where the nitrogen flow rate is 120 sccm and the acetylene flow rate is 35 sccm. Heat the coating chamber to 200°C, keep it warm for 35 minutes, turn off the baking heating, and keep the workpiece warm in a hollow environment for coating. Set the workpiece bias to -120V for the bias power supply, the Cr / Si target current to 15A, and the deposition time to 30 minutes; (5) Deposition of CrSiN film: Keep argon gas flowing, turn off acetylene, increase nitrogen flow rate to 160sccm, lower the temperature in the coating chamber to 150°C, set the bias voltage of the bias power supply to -150V, set the Cr / Si target current to 18A, start deposition, and the deposition time is 10min; (6) Deposition of the second CrSiCN film: Keep argon gas flowing, introduce acetylene into the coating chamber, reduce nitrogen flow, maintain nitrogen flow at 120sccm, acetylene flow at 35sccm, heat the coating chamber to 200°C, keep warm for 35min, turn off baking heating, keep the workpiece warm in a hollow environment, set the workpiece bias to -120V, Cr / Si target current to 13A, start deposition, deposition time 35min; (7) After coating, cool down and remove the workpiece.

[0036] The thickness of each layer of the obtained thin film is: 100nm for the Cr film, 70nm for the first CrSiCN film, 150nm for the CrSiN film, and 200nm for the second CrSiCN film.

[0037] Comparative Example Comparative Example 1 A high hardness coating method The difference between this comparative example and Example 1 is that in this comparative example, in steps (4) and (6), during the deposition of the first CrSiCN film and the second CrSiCN film, thermal insulation coating is not used in the coating chamber, and the temperature in the coating chamber is increased from 100°C to 180°C.

[0038] Comparative Example 2 A high hardness coating method The difference between this comparative example and Example 1 is that in this comparative example, in steps (4) and (6), during the deposition of the first CrSiCN film and the second CrSiCN film, the gas flow rates are controlled as follows: 180 sccm for argon, 100 sccm for nitrogen, and 50 sccm for acetylene.

[0039] Comparative Example 3 The difference between this comparative example and Example 1 is that in this comparative example, in step (5), during the deposition of the CrSiN film, the gas flow rates are controlled to be: 180 sccm for argon and 140 sccm for nitrogen.

[0040] Performance Test: 1. Adhesion: Adopt the hundred-grid test method, use a 1mm hundred-grid knife to cross-score the substrate on the surface of the workpiece, remove the surface debris, stick it on the test piece with 3M610 tape, smooth it and let it stand for 90 seconds, then quickly pull up the tape at 90 degrees to judge the adhesion level, and record the results in Table 1.

[0041] 2. Hardness: The hardness of the film was measured using a HX-1000 Vickers microhardness tester with a load of 0.5 N and a pressure hold of 20 s. The hardness results are recorded in Table 1.

[0042] 3. Wear resistance: The friction and wear performance of the coating was tested using a ball-disc friction and wear tester. The mating parts were 5mm diameter GCrl5 steel balls (hardness 62HRC), the test load was 5N, the linear speed was 0.2m / s, the test time was 1h, and the wear rate was calculated based on the width and depth of the wear scar. The wear rate results are recorded in Table 1.

[0043] Table 1 sample Binding force hardness <![CDATA[Wear resistance mm 3 / (N·m)]]> Example 1 5B 1895HV <![CDATA[4.8×10 -7 ]]> Example 2 5B 1903HV <![CDATA[5.3×10 -7 ]]> Example 3 5B 1887HV <![CDATA[5.0×10 -7 ]]> Comparative Example 1 5B 1604HV <![CDATA[7.5×10 -7 ]]> Comparative Example 2 4B 1263HV <![CDATA[9.4×10 -7 ]]> Comparative Example 3 4B 1348HV <![CDATA[8.9×10 -7 ]]> Data Analysis: According to Table 1, Examples 1-3 are coated according to a high hardness coating method of the present application. By controlling the gas flow ratio, coating time and temperature, the prepared films have better bonding strength and coating adhesion, and more excellent hardness and wear resistance.

[0044] When the gas flow ratio is changed, Comparative Example 2 changes the flow ratio of argon, nitrogen and acetylene in the preparation of CrSiCN film, resulting in changes in the generated crystalline phase structure. Excessive acetylene flow may lead to an increase in free C, which has low strength and preferentially generates cracks in the C-rich area, thereby reducing the overall hardness of the film and causing a high wear rate of the film. The reduction of nitrogen may make part of the crystalline phase structure Cr2N, which has a lower hardness than the CrN structure and a higher friction coefficient. It is easy to react with oxygen in sliding contact to form CrO wear debris, resulting in a high wear rate.

[0045] Comparative Example 3 changes the flow ratio of argon and nitrogen in the preparation of the CrSiN film, resulting in a change in the crystalline phase structure, which may also cause the presence of Cr2N and amorphous Si3N4, affecting the hardness and wear rate of the film.

[0046] In the preparation of the CrSiCN film in Comparative Example 1, the temperature during the coating process changes, resulting in film defects due to the heating temperature, pinhole light transmission phenomenon in the film, and affecting the hardness, wear resistance and other properties of the film.

[0047] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high hardness coating method, characterized in that: The steps include: (1) Preparation: Install Cr target and Cr / Si mixed target in magnetron sputtering coating equipment, clean the workpiece by ultrasonic, dry it and fix it on the rotating rack of the coating chamber of magnetron sputtering coating equipment, evacuate the coating chamber and preheat the workpiece, and start the rotating rack to rotate; (2) Etching: introduce argon gas into the coating chamber with a flow rate of 30-40 sccm, use ion beam to etch the workpiece, and the etching time is 4-5 minutes; (3) Deposition of Cr film: Continue to introduce argon gas into the coating chamber, increase the argon gas flow rate to 170-190sccm, set the Cr target current to 18-20A, start deposition, and the deposition time is 5-7min; (4) Deposition of the first CrSiCN film: Keep argon gas flowing, and introduce nitrogen and acetylene into the coating chamber at the same time, heat the coating chamber to 180-210°C, keep warm for 30-40 minutes, then turn off the heating, start heat preservation coating, set the Cr / Si target current to 15-16A, and the deposition time to 30-32 minutes; (5) Deposition of CrSiN film: Keep argon gas flowing, turn off acetylene, increase nitrogen flow, set Cr / Si target current to 18-20A, start deposition, deposition time 10-12min; (6) Deposition of the second CrSiCN film: Keep argon gas flowing, introduce acetylene, reduce nitrogen flow, heat the coating chamber to 180-210°C, keep warm for 30-40 minutes, then turn off the heating, start heat preservation coating, set the Cr / Si target current to 12-13A, and the deposition time to 35-38 minutes; (7) After coating, cool down and remove the workpiece.

2. A high hardness coating method according to claim 1, characterized in that: In the step (4) and the step (6), the nitrogen flow rate is 120-125 sccm, and the acetylene flow rate is 30-40 sccm.

3. A high hardness coating method according to claim 1, characterized in that: The nitrogen flow rate in step (5) is 160-165 sccm.

4. A high hardness coating method according to claim 1, characterized in that: The ion source voltage in step (2) is 1100-1300V.

5. A high hardness coating method according to claim 1, characterized in that: The mixing ratio of the Cr / Si mixed target in step (1) is Cr:Si=9:

1.

6. A high hardness coating method according to claim 1, characterized in that: The thickness of each layer of the film is: 100-110nm for the Cr film, 60-70nm for the first CrSiCN film, 140-150nm for the CrSiN film, and 200-210nm for the second CrSiCN film.

7. A high hardness coating method according to claim 5, characterized in that: The purity of the Cr target in step (1) is 99.5% or above; the rotation speed of the turntable is 25-30r / min.

8. A high hardness coating method according to claim 1, characterized in that: The coating temperature of step (2), step (3) and step (5) is set at 100-180°C.

9. A high hardness coating method according to claim 1, characterized in that: The magnetron sputtering coating equipment comprises a coating chamber, in which a rotating rack for placing workpieces is arranged, the rotating rack is connected to a reciprocating fixture, the rotating rack is connected to a bias power supply, and a target material and a four-way gas flow control system are arranged in the coating chamber.

10. A high hardness coating method according to claim 9, characterized in that: The bias power supply in step (2) is set to -800 V, the bias power supply in step (3) is set to -80 V, the bias power supply in steps (4) and (6) is set to -120 V, and the bias power supply in step (5) is set to -150 V.