A super-hard wear-resistant film and preparation method thereof

Abstract

The present application relates to the field of protective hard films, and specifically discloses a super-hard wear-resistant film and a preparation method thereof. The super-hard wear-resistant film is a multilayer composite film composed of tantalum carbide doped with chromium, silicon, and nitrogen. The overall thickness of the multilayer composite film is 2.0-3.6μm, and the surface hardness is not less than 1300HV. The super-hard wear-resistant film of the present application can have a higher surface hardness and wear resistance by selecting elements such as chromium, silicon, and nitrogen to cooperate with tantalum carbide, and combining the design of the multilayer structure, which can meet the increasingly stringent market needs.

Description

Technical Field

[0001] The present application relates to the field of protective hard films, specifically, to the field of protective hard films prepared by physical vapor deposition, and more specifically, it relates to a superhard wear-resistant film and a preparation method thereof. Background Art

[0002] Hard film mainly refers to thin film materials with high hardness and excellent wear resistance. Since its hardness is usually much higher than other common metal materials, it is widely used in various fields and plays an important role in improving material performance, protecting fragile surfaces and improving product quality. These fields include but are not limited to the following categories: (1) Hard film is used in the manufacturing of cutting tools, molds, etc. to improve their cutting performance and wear resistance; (2) In electronic products, hard film can be used to protect fragile surfaces such as display screens and touch screens to prevent scratches and damage; (3) Hard film is used on the surface of automotive parts to improve their durability and reliability.

[0003] There are many ways to prepare hard films, including physical vapor deposition (PVD) and chemical vapor deposition (CVD), which can form a dense, high-hardness coating on the surface of various substrates. Among them, PVD is a process that uses certain physical phenomena, such as thermal evaporation of materials or sputtering of atoms on the surface of materials when bombarded by particle beams, to achieve a controllable transfer process of material atoms from the source material to the film. It has the characteristics of high vacuum environment, high film purity, good crystallinity, strong bonding between the film layer and the substrate, and high process repeatability.

[0004] At present, the hard film on the surface of electronic products is usually prepared by single-layer PVD technology. The hard film produced by this technology is thinner, has a more uniform composition and structure, and is simple to operate, easy to control, and low in cost. However, as people's requirements for the surface hardness and wear resistance of electronic products are getting higher and higher, the various properties of the hard film produced by the traditional single-layer PVD technology have gradually failed to meet market demand. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a superhard wear-resistant film and a preparation method thereof.

[0006] In the first aspect, the present application provides a superhard wear-resistant film, which adopts the following technical solution:

[0007] A superhard wear-resistant film is a multilayer composite film composed of tantalum carbide doped with chromium, silicon and nitrogen. The overall thickness of the multilayer composite film is 2.0-3.6 μm, and the surface hardness is not less than 1300 HV.

[0008] Preferably, the surface hardness of the superhard wear-resistant film is not less than 1600 HV.

[0009] Preferably, the surface hardness of the superhard wear-resistant film is 1900-2200 HV.

[0010] Through the above technical solution, the present application combines tantalum carbide with high hardness and high melting point with chromium, silicon, and nitrogen elements to form a multilayer composite film. Compared with the traditional single hard phase or single hard layer mode, the multilayer composite film has higher surface hardness and wear resistance. Specifically, the present application selects chromium, silicon, and nitrogen elements to cooperate with tantalum carbide, and combines the design of the multilayer structure to reduce the residual stress and thermal stress in the film preparation process, reduce the crack driving force, and enhance the bonding strength between the layers of the film, so that the prepared film has higher hardness and wear resistance.

[0011] After testing, the surface hardness of the super-hard wear-resistant film of the present application is not less than 1300HV, while the surface hardness of the traditional hard film is about 1000HV; after 4000 times of steel wool friction, the surface of the super-hard wear-resistant film of the present application has no obvious scratches, and after 4 hours of groove vibration grinding, the film has no damage or falling, while the traditional hard film is more likely to have obvious scratches, damage, and falling after the above friction test. Therefore, the test data shows that the hardness and wear resistance of the super-hard cerebral membrane film of the present application are significantly better than those of the traditional hard film.

[0012] Furthermore, the surface hardness of the ultra-hard wear-resistant film of the present application is not less than 1600HV at the minimum. Furthermore, the surface hardness of the ultra-hard wear-resistant film of the present application can reach 1900HV or above, but since the thickness and hardness of the ultra-hard wear-resistant film are comprehensively considered in the present application, the maximum hardness is limited to 2200HV, that is, the 2200HV of the present application is not the highest hardness that the present application can achieve, but the highest hardness determined from the perspective of both ultra-thinness and high hardness. It is not necessary for those skilled in the art to continue to increase the film thickness on this basis to improve the hardness without creative labor.

[0013] In a second aspect, the present application provides a method for preparing a superhard wear-resistant film, which adopts the following technical solution:

[0014] A method for preparing a superhard wear-resistant film comprises the following steps:

[0015] Under the conditions of gas pressure of 0.15-0.25Pa, bias voltage of 98-102V and inert gas protection, a pure Cr layer is deposited on the surface of the substrate for 25-35 minutes; the bias voltage is adjusted to 118-122V, and a Ta-CrSiN layer is deposited on the surface of the pure Cr layer for 25-35 minutes; the bias voltage is adjusted to 138-142V, and a first CrSiCN layer is deposited on the surface of the Ta-CrSiN layer for 20-30 minutes.

[0016] Through the above technical scheme, the present application first deposits a pure Cr layer on the surface of the substrate for a certain time under certain bias conditions, so that the thickness of the pure Cr layer reaches 0.1-0.3μm, and then deposits a Ta-CrSiN layer on the pure Cr surface for a certain time under certain bias conditions, so that the thickness of the Ta-CrSiN layer reaches 0.3-0.6μm, and then continues to deposit a first CrSiCN layer on the surface of the Ta-CrSiN layer for a certain time under certain bias conditions, so that the thickness of the first CrSiCN layer reaches 0.4-0.6μm.

[0017] This application controls the bias voltage and deposition time during deposition, so that the surface hardness after the pure Cr layer is deposited is 800-1000HV, the surface hardness after the Ta-CrSiN layer is deposited is 1000-1300HV, and the surface hardness after the first CrSiCN layer is deposited is 1300-1600HV. The hardness of the three layers is in a gradually increasing pattern, the residual stress, thermal stress, and crack driving force are low, and the bonding strength between the film layers is high, so that the hardness and wear resistance of the final superhard wear-resistant film are high. If the deposition conditions of each layer of deposition change, the thickness of the film layer and the composition content of the film layer will change, and the hardness of each layer will also change accordingly, and the trend of gradient growth cannot be maintained. When the hardness span between the two layers of film is large, it will lead to poor bonding strength between the film layers, resulting in cracking, film collapse and other phenomena.

[0018] Preferably, the bias voltage is adjusted to 158-162 V, and the second CrSiCN layer is deposited on the surface of the first CrSiCN layer for a deposition time of 95-105 minutes.

[0019] Through the above technical solution, the present application deposits a second CrSiCN layer on the surface of the first CrSiCN layer for a certain period of time under certain bias conditions, so that the thickness of the second CrSiCN layer reaches 0.4-0.6μm, further improving the surface hardness and wear resistance of the superhard wear-resistant film. After testing, the surface hardness of the superhard wear-resistant film obtained after the second CrSiCN layer is deposited can reach 1600-1900HV.

[0020] Preferably, the bias voltage is adjusted to 178-182 V, and the third CrSiCN layer is deposited on the surface of the second CrSiCN layer for a deposition time of 95-105 minutes.

[0021] The surface composition of the third CrSiCN layer includes Si 65-70wt%, Cr 15-25wt%, C 10-15wt% and N 5-10wt%.

[0022] Through the above technical solution, the present application deposits a third CrSiCN layer on the surface of the second CrSiCN layer for a certain period of time under certain bias conditions, so that the thickness of the third CrSiCN layer reaches 0.8-1.5 μm, further improving the surface hardness and wear resistance of the superhard wear-resistant film. After testing, the surface hardness of the superhard wear-resistant film obtained after the third CrSiCN layer is deposited can reach 1900-2200 HV.

[0023] Furthermore, the substrate is arc cleaned for 3-5 minutes at a temperature of 145-155° C., a gas pressure of 0.15-0.25 Pa, a bias voltage of 250-350 V, and a duty cycle of 48-52%, and then a pure Cr layer is deposited.

[0024] Furthermore, the substrate is firstly ultrasonically cleaned and then heated to 145-155°C.

[0025] Through the above-mentioned technical scheme, the present application fully removes pollutants such as oil, dust, and oxides on the surface of the substrate, reduces the possibility that pollutants on the surface of the substrate are incorporated into the deposited layer as impurities during the deposition process, thereby affecting the purity, structure and performance of the film, so that the deposition process of the super-hard wear-resistant film can proceed smoothly, ensuring the deposition quality and performance of the super-hard wear-resistant film.

[0026] In summary, this application has the following beneficial technical effects:

[0027] 1. The present application selects chromium, silicon, nitrogen and other elements to cooperate with tantalum carbide, and combines the design of multi-layer structure, which can reduce the residual stress and thermal stress in the film preparation process, reduce the crack driving force, and enhance the bonding strength between the layers of the film, so that the prepared film has higher surface hardness and wear resistance;

[0028] 2. The surface hardness of the super-hard wear-resistant film of the present application is not less than 1300 HV. After being rubbed with steel wool 4000 times, there are no obvious scratches on the surface. After being grooved and vibrated for 4 hours, the film is not damaged or dropped.

[0029] 3. The present application controls the bias voltage and deposition time during deposition so that the hardness of the ultra-hard wear-resistant film increases layer by layer. The bonding strength between the film layers is high, which significantly reduces the possibility of film cracking, film collapse and other phenomena. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1( a ) is a graph showing the results of a steel wool friction test of superhard wear-resistant films prepared in Examples 1-9 of the present application;

[0031] FIG1( b ) is a graph showing the steel wool friction test results of the hard film prepared in Comparative Example 1-2;

[0032] Figure 2(a)-Figure 2(b) This is a graph showing the results of the groove vibration wear test of the superhard wear-resistant films prepared in Examples 1-9 of the present application;

[0033] Figure 3(a)-Figure 3(b) This is a graph showing the results of the groove vibration wear resistance test of the hard film prepared in Comparative Example 1-2. DETAILED DESCRIPTION

[0034] The present application is further described in detail below in conjunction with the accompanying drawings, embodiments and comparative examples.

[0035] In a specific embodiment of the present application, the preparation process adopts a 1915 type vacuum coating machine; the target material configuration includes 1 pair of Si targets, 2 pairs of Ta targets, and 1 pair of Cr targets; 4 medium frequency magnetron sputtering power supplies; and the gases include Ar, N2, and C2H2.

[0036] In the present application, the substrate may be cemented carbide, high-speed steel, ceramic, or metal ceramic, and those skilled in the art may select the substrate according to actual needs.

[0037] Example 1

[0038] A method for preparing a superhard wear-resistant film comprises the following steps:

[0039] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 145°C for insulation. When the vacuum degree reaches 0.005Pa, argon gas is introduced to make the system pressure reach 0.15Pa. The bias power supply is turned on, the bias voltage is set to 250V, the duty cycle is 45%, and the arc target is turned off after arc cleaning for 5 minutes;

[0040] S2, set the bias voltage to 98V and adjust the argon gas flow rate to 300cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the substrate surface. The deposition time is 35 minutes, and the thickness of the pure Cr layer is 0.3μm;

[0041] S3, adjust the bias voltage to 118V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 35 minutes, and the thickness of the Ta-CrSiN layer is 0.6μm.

[0042] S4, adjusting the bias voltage to 138V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.6μm.

[0043] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0044] Example 2

[0045] A method for preparing a superhard wear-resistant film comprises the following steps:

[0046] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 155°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.25Pa. The bias power supply is turned on, the bias voltage is set to 350V, the duty cycle is 52%, and the arc target is turned off after arc cleaning for 3 minutes;

[0047] S2, set the bias voltage to 102V and adjust the Ar flow rate to 300cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the substrate surface. The deposition time is 25 minutes, and the thickness of the pure Cr layer is 0.1 μm;

[0048] S3, adjust the bias voltage to 122V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.3μm;

[0049] S4, adjusting the bias voltage to 142V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 20 minutes, and the thickness of the Ta-CrSiN layer is 0.4 μm.

[0050] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0051] Example 3

[0052] A method for preparing a superhard wear-resistant film comprises the following steps:

[0053] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0054] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0055] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0056] S4, adjusting the bias voltage to 140V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0057] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0058] Example 4

[0059] A method for preparing a superhard wear-resistant film comprises the following steps:

[0060] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0061] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0062] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0063] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0064] S42, adjusting the bias voltage to 158 V, and continuing to deposit the second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 105 minutes, and the thickness of the second CrSiCN layer is 0.6 μm;

[0065] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0066] Example 5

[0067] A method for preparing a superhard wear-resistant film comprises the following steps:

[0068] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0069] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0070] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0071] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0072] S42, adjusting the bias voltage to 162 V, and continuing to deposit a second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 95 minutes, and the thickness of the second CrSiCN layer is 0.4 μm;

[0073] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0074] Example 6

[0075] A method for preparing a superhard wear-resistant film comprises the following steps:

[0076] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0077] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0078] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0079] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0080] S42, adjusting the bias voltage to 160 V, and continuing to deposit the second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 100 minutes, and the thickness of the second CrSiCN layer is 0.5 μm;

[0081] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0082] Example 7

[0083] A method for preparing a superhard wear-resistant film comprises the following steps:

[0084] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0085] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the substrate surface. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0086] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0087] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0088] S42, adjusting the bias voltage to 160 V, and continuing to deposit the second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 100 minutes, and the thickness of the second CrSiCN layer is 0.5 μm;

[0089] S43, adjusting the bias voltage to 178 V, and continuing to deposit the third CrSiCN layer on the surface of the second CrSiCN layer, the deposition time is 105 minutes, and the thickness of the second CrSiCN layer is 1.5 μm;

[0090] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0091] Example 8

[0092] A method for preparing a superhard wear-resistant film comprises the following steps:

[0093] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0094] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0095] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0096] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0097] S42, adjusting the bias voltage to 160 V, and continuing to deposit the second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 100 minutes, and the thickness of the second CrSiCN layer is 0.5 μm;

[0098] S43, adjusting the bias voltage to 182 V, and continuing to deposit the third CrSiCN layer on the surface of the second CrSiCN layer, the deposition time is 95 minutes, and the thickness of the second CrSiCN layer is 0.8 μm;

[0099] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0100] Example 9

[0101] A method for preparing a superhard wear-resistant film comprises the following steps:

[0102] S1. After ultrasonic cleaning, the substrate is placed in the vacuum chamber of a 1915 vacuum coating machine, evacuated and heated to 150°C for insulation. When the vacuum degree reaches 0.005Pa, Ar is introduced to make the system pressure reach 0.2Pa. The bias power supply is turned on, the bias voltage is set to 300V, the duty cycle is 50%, and the arc target is turned off after arc cleaning for 4 minutes;

[0103] S2, set the bias voltage to 100 V and adjust the Ar flow rate to 300 cm 3 / s, turn on the Cr target power supply, and start to deposit a pure Cr layer on the surface of the substrate. The deposition time is 30 minutes, and the thickness of the pure Cr layer is 0.2μm;

[0104] S3, adjust the bias voltage to 120V, and the flow rate to 100cm 3 / s nitrogen, and simultaneously open two pairs of Ta targets and one pair of Si targets to deposit a Ta-CrSiN layer on the surface of the pure Cr layer. The deposition time is 30 minutes, and the thickness of the Ta-CrSiN layer is 0.45μm.

[0105] S41, adjusting the bias voltage to 140 V, turning off the two pairs of Ta targets, and slowly introducing C2H2 in a step-by-step manner to deposit the first CrSiCN layer on the surface of the pure Ta-CrSiN layer. The deposition time is 25 minutes, and the thickness of the Ta-CrSiN layer is 0.5 μm.

[0106] S42, adjusting the bias voltage to 160 V, and continuing to deposit the second CrSiCN layer on the surface of the first CrSiCN layer, the deposition time is 100 minutes, and the thickness of the second CrSiCN layer is 0.5 μm;

[0107] S43, adjusting the bias voltage to 180 V, and continuing to deposit the third CrSiCN layer on the surface of the second CrSiCN layer, the deposition time is 100 minutes, and the thickness of the second CrSiCN layer is 1.15 μm;

[0108] S5. Turn off the Si target, Cr target, bias power supply, turn off all gases, end the coating, and obtain an ultra-hard and wear-resistant film.

[0109] Comparative Example 1

[0110] A single-layer film is deposited on the surface of a substrate using PVD technology to obtain a traditional hard film, wherein the surface composition of the hard film is Si 40-50wt%, Cr 35-45wt%, C 10-20wt%, and N 2-8wt%.

[0111] Comparative Example 2

[0112] A hard film is obtained by alternately depositing a plurality of titanium-nitride aluminum layers and a plurality of boron nitride layers on the surface of a substrate using PVD technology. The thickness of each titanium-nitride aluminum layer and each boron nitride layer is 3-15 nm. The overall thickness of the hard film is 1.15 μm. The composition content of the hard film is Ti 46.0-46.6 wt%, Al 25.6-26.2 wt%, and N 27.2-28.4 wt%.

[0113] Comparative Example 3

[0114] The difference from Example 3 is that the Ta target is not turned on in step S3, and C2H2 is not introduced in step S4. The rest is the same as Example 3.

[0115] Comparative Example 4

[0116] The difference from Example 3 is that the bias voltage in step S3 is changed to 140V, and the bias voltage in step S4 is adjusted to 160V. The rest is the same as Example 3.

[0117] Comparative Example 5

[0118] The difference from Example 3 is that the bias voltage in step S4 is changed to 160V, and the rest is the same as Example 3.

[0119] Comparative Example 6

[0120] The difference from Example 6 is that the bias voltage in step S42 is changed to 180V, and the rest is the same as Example 6.

[0121] Comparative Example 7

[0122] The difference from Example 9 is that the bias voltage in step S43 is changed to 200V, and the rest is the same as Example 6.

[0123] Performance Testing

[0124] 1. The surface hardness of Examples 1-9 and Comparative Examples 1-7 was tested by using a Vickers hardness tester, and the test results are shown in Table 1; 2. The wear resistance of Examples 1-9 and Comparative Examples 1-7 was tested, and the wear resistance test mainly included a steel wool friction test and a slot vibration wear test; the conditions of the steel wool friction test were as follows: using special steel wool, applying a load of 500gf, the test head area was 2×2cm, rubbing back and forth on the sample surface 4000 times at a speed of 40 turns / min and a stroke of 30mm, and observing the thin film. The scratch degree of the film surface, the result is shown in Figure 1; the conditions of the slot vibration wear test are: first prepare 3 parts of pre-ground conical abrasives and 1 part of pre-ground pyramidal abrasives, a total of about 15L, add them to the grinding tank of the vibration friction equipment, then add the sample, use a pipette to absorb 4mL of cleaning solution, and dilute it to 500mL with water and add it to the grinding tank, start the test, add 500mL of water every 60 minutes during the test, until the specified 4-hour test time, observe the degree of wear on the film surface, the results are shown in Figures 2-3.

[0125] Table 1 Test results of each layer and final surface hardness Unit: HV

[0126]

[0127]

[0128] Data Analysis:

[0129] From Table 1, Figure 1(a) and Figure 2(a)-Figure 2(b) It can be seen that the surface hardness of the super-hard wear-resistant film prepared in Examples 1-9 of the present application can reach 1300 HV or above. After being rubbed with steel wool 4000 times, there are no obvious scratches on the surface. After being grooved and vibrated for 4 hours, the surface of the film is still intact without any damage or falling off. The experimental results show that the super-hard wear-resistant film prepared in the present application has high surface hardness and wear resistance.

[0130] Among them, the difference between Example 4-6 and Example 3 is that a second CrSiCN layer is further deposited on the first CrSiCN layer. It can be seen from Table 1 that the surface hardness of the superhard wear-resistant film obtained in Example 4-6 reaches 1600-1900HV, which is higher than 1460HV of Example 3. Experimental data show that further depositing a second CrSiCN layer on the surface of the first CrSiCN layer can further improve the surface hardness of the superhard wear-resistant film.

[0131] The difference between Example 7-9 and Example 6 is that a third CrSiCN layer is further deposited on the second CrSiCN layer. As can be seen from Table 1, the surface hardness of the superhard wear-resistant film obtained in Example 7-9 reaches 1900-2200 HV, which is higher than 1850 HV of Example 6. Experimental data show that further depositing a third CrSiCN layer on the surface of the second CrSiCN layer can further improve the surface hardness of the superhard wear-resistant film.

[0132] Comparative Examples 1-2 are both conventional hard films, wherein Comparative Example 1 is a single-layer hard film and Comparative Example 2 is a multi-layer hard film. As can be seen from Table 1, the surface hardness of Comparative Example 1 is 1000 HV and the surface hardness of Comparative Example 2 is 1230 HV, both lower than 1300-1600 HV of Examples 1-3. Figure 3(a)-Figure 3(b) It can be seen that after rubbing with steel wool 4000 times, the surface of the hard film of comparative example 1-2 showed obvious scratches, and after 4 hours of groove vibration grinding, the surface of the film showed damage and falling. The experimental data show that the superhard wear-resistant film prepared in this application has better hardness and wear resistance than the traditional hard film.

[0133] The difference between Comparative Example 3 and Example 3 is that the prepared film does not contain tantalum carbide. As can be seen from Table 1, the surface hardness of Comparative Example 3 is 1180 HV, which is significantly lower than 1460 HV of Example 3. Experimental data show that the addition of tantalum carbide can significantly improve the hardness and wear resistance of the film.

[0134] The difference between Comparative Example 4 and Example 3 is that the bias voltage in step S3 is increased from 120V to 140HV. The experimental results show that the film cracks after the Ta-CrSiN layer is deposited in Comparative Example 4, so the surface hardness cannot be measured. The difference between Comparative Example 5 and Example 3 is that the bias voltage in step S4 is increased from 140V to 160HV. The experimental results show that the film cracks after the first CrSiCN layer is deposited in Comparative Example 5, so the surface hardness cannot be measured. The difference between Comparative Example 6 and Example 6 is that the bias voltage in step S42 is increased from 160V to 180HV. The experimental results show that the film cracks after the second CrSiCN layer is deposited in Comparative Example 6, so the surface hardness cannot be measured. The difference between Comparative Example 7 and Example 9 is that the bias voltage in step S43 is increased from 160V to 180HV. The experimental results show that the film cracks after the third CrSiCN layer is deposited in Comparative Example 6, so the surface hardness cannot be measured. It can be seen that when the deposition voltage changes, due to the large difference in hardness between any two film layers, the bonding strength between the film layers is poor, and then cracking and film collapse occur.

[0135] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a superhard wear-resistant film, characterized in that: The following steps are involved: Under the conditions of gas pressure of 0.15-0.25Pa, bias voltage of 98-102V and inert gas protection, a pure Cr layer is deposited on the surface of the substrate for 25-35 minutes; the bias voltage is adjusted to 118-122V, and a Ta-CrSiN layer is deposited on the surface of the pure Cr layer for 25-35 minutes; the bias voltage is adjusted to 138-142V, and a first CrSiCN layer is deposited on the surface of the Ta-CrSiN layer for 20-30 minutes; the bias voltage is adjusted to 158-162V, and a second CrSiCN layer is deposited on the surface of the first CrSiCN layer for 95-105 minutes; the bias voltage is adjusted to 178-182V, and a third CrSiCN layer is deposited on the surface of the second CrSiCN layer for 95-105 minutes; the surface components of the third CrSiCN layer include Si 65-70wt%, Cr 15-25wt%, C 10-15wt% and N 5-10wt%.

2. The method for preparing a superhard wear-resistant film according to claim 1, characterized in that: The substrate is arc cleaned for 3-5 minutes at a temperature of 145-155° C., a gas pressure of 0.15-0.25 Pa, a bias voltage of 250-350 V, and a duty cycle of 48-52%, and then a pure Cr layer is deposited.

3. The method for preparing a superhard wear-resistant film according to claim 2, characterized in that: The substrate is firstly cleaned by ultrasonic and then heated to 145-155°C.

4. A superhard wear-resistant film prepared by the preparation method according to claim 1, characterized in that: The multilayer composite film is composed of tantalum carbide doped with chromium, silicon and nitrogen. The overall thickness of the multilayer composite film is 2.0-3.6 μm, and the surface hardness is not less than 1300 HV.

5. The superhard wear-resistant film according to claim 1, characterized in that: The surface hardness of the super-hard wear-resistant film is not less than 1600 HV.

6. The superhard wear-resistant film according to claim 5, characterized in that: The surface hardness of the super-hard wear-resistant film is 1900-2200 HV.

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