Superhard and high-toughness nano composite coating and preparation method thereof

Abstract

The invention provides a preparation method of a superhard and high-toughness nano-composite coating. The preparation method comprises the following steps: 1) pre-cleaning a matrix; 2) carrying out glow discharge cleaning and ion cleaning on the substrate; 3) depositing a transition layer on the substrate by adopting a magnetic filtration vacuum cathode arc co-deposition method; and (4) depositing on the transition layer by adopting a magnetic filtration vacuum cathode arc co-deposition method to form the TiAlSiVN nano-composite coating. The invention provides the superhard and high-toughness nano composite coating, and the transition layer is sandwiched between the substrate and the TiAlSiVN nano composite coating. Controllable preparation of the super-hard and high-toughness nano composite coating is achieved at the low temperature smaller than or equal to 200 DEG C, the nano hardness of the coating ranges from 40.2 GPa to 44.6 GPa, the fracture toughness ranges from 3.3 MPa.m < 1 / 2 > to 3.8 MPa.m < 1 / 2 >, the defects that an existing coating is not compact in structure, large in surface roughness, insufficient in hardness and toughness and the like are overcome, and the super-hard and high-toughness nano composite coating is widely applied to the fields of tools, molds and the like.

Description

Technical Field

[0001] This invention relates to the field of magnetic filtration vacuum cathode arc co-deposition nanocomposite coating technology, specifically to an ultra-hard and high-toughness nanocomposite coating and its preparation method. Background Technology

[0002] Hard surface protective coatings are widely used in the processing of mechanical parts, cutting tools, molds, and hydrogen fuel cell engines. By depositing a high-hardness surface protective coating on the surface of parts, cutting tools, molds, etc., their service life can be effectively improved, thereby improving the production and operation efficiency of the system, which has significant economic value.

[0003] Taking tool coatings as an example, compared with uncoated tools, coated tools have higher surface hardness, allowing for higher cutting speeds during machining, thus improving machining efficiency; or, at the same cutting speed, increasing tool life. Improving the hardness and toughness of the hard surface protective coating is key to enhancing surface protection performance.

[0004] Traditional methods for preparing hard nanocomposite coatings suffer from defects such as non-dense structure, high surface roughness, and insufficient hardness and toughness. In existing technologies, it is difficult to simultaneously achieve high hardness and high toughness in hard surface protective coatings. High-hardness hard surface protective coatings, due to their low toughness, are prone to cracking and detachment under external impact loads, leading to premature failure. Coatings prepared using existing CVD or common PVD techniques have numerous structural defects and poor density. Existing coating preparation methods inevitably result in the formation of nanoscale micropores or cracks within the coating during the deposition process. These defects are usually caused by dust particles or other random events during film growth. These defects cause microcracks to propagate and extend along these defects during use, leading to premature cracking and detachment. Summary of the Invention

[0005] The objective of this invention is to provide a method for preparing an ultra-hard and highly tough nanocomposite coating. Another objective of this invention is to provide an ultra-hard and highly tough nanocomposite coating.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing an ultra-hard and highly tough nanocomposite coating includes the following steps performed sequentially: 1) Prepare the substrate by pre-cleaning it; 2) Perform glow discharge cleaning and ion cleaning on the substrate; 3) A transition layer is deposited on the substrate using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating is deposited on the transition layer using a magnetically filtered vacuum cathode arc co-deposition method.

[0007] Preferably, in step 1), the pre-cleaning specifically includes: ultrasonically cleaning the substrate with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the substrate surface. The substrate is stainless steel, high-speed steel, or hard alloy.

[0008] Preferably, in step 2), the glow discharge cleaning and ion cleaning specifically include: after completing the pre-cleaning, placing the substrate in a vacuum chamber and mounting it on the sample stage, evacuating to below 0.005 Pa, then introducing argon gas with a flow rate of 20-200 sccm, a working pressure of 0.3-2.0 Pa in the vacuum chamber, a starting negative bias of 200-600 V, and starting glow discharge cleaning for 10-20 min; Then start the Ti target, with an arc current of 70-130A and a bending current of 1.5-3A. Adjust the negative bias voltage to 400-800V for ion cleaning, and the ion cleaning time is 5-30 minutes.

[0009] Preferably, in step 3), the method for preparing the transition layer specifically includes: using a cathode target, introducing argon gas with a flow rate of 10-200 sccm into the vacuum chamber, the working gas pressure being 0.3-2.0 Pa, the arc current of the cathode target being 70-130 A, the bending current being 1.5-3 A, the negative bias voltage being 50-200 V, and depositing a transition layer on the surface of the substrate, wherein the thickness of the transition layer is 0.1-0.5 μm; The cathode target is a pure Ti target, a pure V target, a TiAl target, or a TiAlSi target, and a Ti transition layer, a V transition layer, a TiAl transition layer, or a TiAlSi transition layer is deposited on the substrate surface accordingly.

[0010] Preferably, in step 4), the preparation method of the TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, with the arc current of each cathode target being 70-130A, the current of each bend being 1.5-3A, the substrate negative bias voltage being set to 0-200 V, the argon flow rate being 10-150 sccm, and the nitrogen flow rate in the vacuum chamber being linearly increased to 30-50 sccm within 5 min, so that the pressure of the mixed gas in the vacuum chamber is 0.5-3.0 Pa, and the deposition time is 120 minutes; The four types of cathode targets in the four channels aim to achieve the TiAlSiV combination. Elemental Si is not selected as the target material alone. Ti, Al and V elements are combined to form unary, binary or ternary alloys as cathode targets.

[0011] Preferably, in step 4), the four-channel magnetic filter vacuum cathode arc target is a Ti target, a TiSi target, a V target, and an Al target, respectively.

[0012] An ultra-hard and high-toughness nanocomposite coating is prepared by any one of the above-described methods for preparing an ultra-hard and high-toughness nanocomposite coating, wherein the transition layer is sandwiched between the substrate and the TiAlSiVN nanocomposite coating. The thickness of the TiAlSiVN nanocomposite coating is 5μm-8μm; The TiAlSiVN nanocomposite coating comprises the following elements by mass percentage: 5%-8% Al, 3%-5% Si, 8%-10% V, 45%-55% N, and the balance Ti.

[0013] This application has achieved the following beneficial technical effects: This application proposes an ultra-hard and high-toughness nanocomposite coating and its preparation method, particularly an ultra-hard and high-toughness nanocomposite coating system containing TiAlSiVN and its preparation method.

[0014] This invention employs a four-channel magnetically filtered vacuum cathode arc co-deposition system. The outlets of the four 90° bent magnetic filters are on the same side, and the sample stage is located on the plane of the magnetic filter outlets, with the same distance from the four magnetic filter outlets. The multi-channel magnetically filtered vacuum cathode arc system enables the deposition of TiAlSiVN nanocomposite coatings with adjustable multi-component composition (the target element of each channel is adjustable). The magnetic filters remove incompletely ionized ion clusters, microdroplets, and other components that easily generate micro-defects in the coating from the deposition plasma, thus achieving uniform and dense nanocomposite coating deposition.

[0015] In this application, the coating structure is as follows: a transition layer is closest to the substrate, the top layer is a TiAlSiVN nanocomposite coating, and between the transition layer and the TiAlSiVN nanocomposite coating is a TiAlSiVN layer with gradually increasing N content. A TiAlSiVN ultra-hard and high-toughness nanocomposite coating was prepared on 316L stainless steel, and its nanohardness and fracture toughness were tested. The nanohardness of the TiAlSiVN nanocomposite coating was 40.2-44.6 GPa, and the fracture toughness was 3.3-3.8 MPa·m. 1 / 2 .

[0016] This application proposes a high-performance, ultra-hard and high-toughness nanocomposite coating and its preparation method, which overcomes the defects of hard nanocomposite coatings prepared by traditional methods, such as non-dense structure, large surface roughness, and insufficient hardness and toughness. It can be widely used in mechanical parts, cutting tools, molds, hydrogen fuel cell engine processing and other fields.

[0017] Compared with the prior art, the present invention proposes an ultra-hard and high-toughness nanocomposite coating with TiAlSiVN composition. This coating obtains a uniform and dense amorphous-coated nanocrystalline composite structure through special composition design and deposition process, which solves the inherent contradiction between coating hardness and toughness.

[0018] This invention provides a hard surface protective coating that can maintain high hardness while possessing strong toughness (abrasion resistance, fatigue resistance, and long lifespan).

[0019] The coating prepared by this invention can significantly reduce micro-defects and micropores in the coating, inhibit the initiation and propagation of micro-cracks along defects during the use of the coating, and significantly improve the toughness of the coating.

[0020] In this application, due to the inherent contradiction between high hardness and toughness, existing hard surface protective coatings can only choose between high hardness and toughness. High-hardness surface protective coatings often have low toughness, while high-toughness surface protective coatings have difficulty increasing hardness. Existing high-hardness surface protective coatings, due to their poor toughness, are prone to accelerated initiation and propagation of microcracks under impact loads, leading to coating breakage, peeling, and premature failure. The coating prepared by this invention has both high hardness and high toughness. The high-toughness hard coating has strong wear resistance and can suppress the initiation and propagation of microcracks in the coating under impact loads, avoiding catastrophic failure and significantly improving the service life of the coating.

[0021] In this application, existing coatings prepared using CVD technology suffer from numerous structural defects and poor density. These defects can lead to the propagation and extension of microcracks during use, resulting in premature breakage and detachment. The coating prepared in this application reduces microdefects generated during the coating deposition process. This invention employs a multi-channel magnetically filtered vacuum cathode arc deposition process, avoiding microparticle defects that are difficult to suppress during conventional PVD deposition. Simultaneously, the high-density ion beam bombardment significantly improves the coating density and reduces microdefects within the coating.

[0022] Furthermore, based on the hard surface protective coating, this invention can significantly improve the coating's ability to withstand impact loads, enhance its fatigue resistance, and significantly extend its service life by increasing the coating's toughness. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the working principle of a method for preparing an ultra-hard and highly tough nanocomposite coating according to an embodiment of the present invention. Figure 1This is a simplified diagram of a four-channel magnetic filter vacuum cathode arc deposition equipment. The four tubes on the left side of the diagram are 90° bent magnetic filters. The coil current on the bent tube is the bent tube current. The plasma generated by the cathode target is transmitted inside the bent tube. The gas introduced is argon and nitrogen. Figure 2 This is a cross-sectional structural diagram of an ultra-hard and highly tough nanocomposite coating provided in an embodiment of the present invention; In the diagram: 101 Cathode target, 102 Bent tube magnetic filter, 103 Plasma generated by the cathode target, 104 Vacuum chamber; 201 Substrate, 202 Transition layer, 203 TiAlSiVN nanocomposite coating. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, and not all of them. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This application provides a method for preparing an ultra-hard and highly tough nanocomposite coating, comprising the following steps performed sequentially: 1) Prepare substrate 201 and pre-clean it; 2) Perform glow discharge cleaning and ion cleaning on substrate 201; 3) A transition layer 202 is deposited on the substrate 201 using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating 203 is deposited on the transition layer 202 using a magnetically filtered vacuum cathode arc co-deposition method.

[0026] In one embodiment of this application, step 1) specifically includes: ultrasonically cleaning the substrate 201 with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the surface of the substrate 201. The substrate 201 is stainless steel, high-speed steel or cemented carbide.

[0027] In one embodiment of this application, step 2) specifically includes glow discharge cleaning and ion cleaning: after completing the pre-cleaning, the substrate 201 is placed in the vacuum chamber 104 and mounted on the sample stage. After evacuating to below 0.005 Pa, argon gas is introduced with a flow rate of 20-200 sccm. The working pressure of the vacuum chamber 104 is 0.3-2.0 Pa, the starting negative bias voltage is 200-600 V, and glow discharge cleaning is started for 10-20 min. Then start the Ti target, with an arc current of 70-130A and a bending current of 1.5-3A. Adjust the negative bias voltage to 400-800V for ion cleaning, and the ion cleaning time is 5-30 minutes.

[0028] In one embodiment of this application, step 3) specifically includes the following method for preparing the transition layer 202: using a cathode target 101, introducing argon gas with a flow rate of 10-200 sccm into a vacuum chamber 104, with a working pressure of 0.3-2.0 Pa, an arc current of 70-130 A, a bending current of 1.5-3 A, and a negative bias voltage of 50-200 V, depositing a transition layer 202 on the surface of the substrate 201, wherein the thickness of the transition layer 202 is 0.1-0.5 μm; The cathode target 101 is a pure Ti target, a pure V target, a TiAl target, or a TiAlSi target, and a Ti transition layer, a V transition layer, a TiAl transition layer, or a TiAlSi transition layer are deposited on the surface of the substrate 201 accordingly.

[0029] In one embodiment of this application, step 4) of the preparation method of TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, the arc current of each cathode target 101 is 70-130A, the current of each bend is 1.5-3A, the substrate negative bias voltage is set to 0-200 V, the argon flow rate is 10-150 sccm, the nitrogen flow rate in the vacuum chamber 104 is linearly increased to 30-50 sccm within 5 min, so that the gas pressure of the mixed gas in the vacuum chamber 104 is 0.5-3.0 Pa, and the deposition time is 120 minutes; The four types of cathode targets for the four channels can achieve the TiAlSiV combination. Elemental Si is not selected as the target material alone. Ti, Al and V elements are used to form unary, binary or ternary alloys as cathode targets.

[0030] In one embodiment of this application, in step 4), the four-channel magnetic filter vacuum cathode arc target is a Ti target, a TiSi target, a V target, and an Al target, respectively.

[0031] This application provides an ultra-hard and high-toughness nanocomposite coating, which is prepared by any of the above-described methods for preparing an ultra-hard and high-toughness nanocomposite coating, wherein the transition layer 202 is sandwiched between the substrate 201 and the TiAlSiVN nanocomposite coating 203. The thickness of the TiAlSiVN nanocomposite coating 203 is 5μm-8μm; The TiAlSiVN nanocomposite coating 203 comprises the following elements by mass percentage: 5%-8% Al, 3%-5% Si, 8%-10% V, 45%-55% N, and the balance Ti.

[0032] The working principle of the method for preparing an ultra-hard and high-toughness nanocomposite coating provided in this application to solve the above-mentioned technical problems is as follows: Multi-channel magnetic filtration vacuum cathode arc co-deposition method: Based on plasma 103 generated by cathode arc discharge, and by adding a magnetic filter during the plasma 103 transport process, large particles and neutral particles generated by the arc source are effectively eliminated. This application uses a multi-channel magnetic filtration vacuum cathode arc deposition system composed of four sets of individual arc sources and +90° bent tube magnetic filters 102. The outlets of the four sets of filters are coplanar, realizing the co-deposition of multiple components. During the plasma transport process in the 90° bent tube filter, electrons and positive ions, under the action of a magnetic field, follow a spiral trajectory around the magnetic force. Linear motion passes through a magnetic filter. Neutral particles or microparticles and microdroplets with a small amount of charge have a large radius of motion in the magnetic field due to their low charge-to-mass ratio. They collide with the wall of the bend and adhere to it. This allows for the generation of a high-density plasma beam with extremely high ionization rate at the 90° bend outlet, which almost completely filters out macroscopic particles. Ultimately, this achieves ion beam deposition with ultra-high ionization rate (close to 100%) and high ion energy flux. This fundamentally avoids micro-defects caused by macroscopic particles during coating deposition. At the same time, the high-density ion beam bombardment can significantly improve the density of the coating and reduce the density of micro-defects in the coating. A dense coating with low defect density is a necessary condition for obtaining an ultra-hard and high-toughness coating.

[0033] The methods and apparatus not described in detail in this invention are all prior art and will not be elaborated further.

[0034] To better understand the present invention, the following embodiments are provided for further detailed description of the present invention, but they should not be construed as limiting the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are also considered to fall within the protection scope of the present invention.

[0035] Example 1 A method for preparing an ultra-hard and highly tough nanocomposite coating includes the following steps performed sequentially: 1) Prepare substrate 201 and pre-clean it; 2) Perform glow discharge cleaning and ion cleaning on substrate 201; 3) A transition layer 202 is deposited on the substrate 201 using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating 203 was deposited on the transition layer 202 using a magnetically filtered vacuum cathode arc co-deposition method; In step 1), the pre-cleaning specifically includes: ultrasonically cleaning the substrate 201 with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the surface of the substrate 201. The substrate 201 is 316L stainless steel; In step 2), the glow discharge cleaning and ion cleaning specifically include: after completing the pre-cleaning, the substrate 201 is placed in the vacuum chamber 104 and mounted on the sample stage. After evacuating to below 0.005 Pa, argon gas is introduced with a flow rate of 60 sccm. The working pressure of the vacuum chamber 104 is 0.8 Pa, the starting negative bias voltage is 400 V, and glow discharge cleaning is started for 10-20 min. Then start the Ti target, with an arc current of 110A and a bending current of 1.5A. Adjust the negative bias voltage to 800V for ion cleaning, and the ion cleaning time is 10 minutes. In step 3), the preparation method of the transition layer 202 specifically includes: using a cathode target 101, introducing argon gas with a flow rate of 60 sccm into a vacuum chamber 104, with a working gas pressure of 0.8 Pa, an arc current of 110 A for the cathode Ti target, a bending current of 1.5 A, and a negative bias voltage of 50 V, depositing a Ti transition layer 202 on the surface of the substrate 201, wherein the thickness of the transition layer 202 is 0.4 μm; The cathode target 101 is a pure Ti target, and a Ti transition layer is deposited on the surface of the substrate 201 accordingly. In step 4), the preparation method of the TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, selecting a combination of Ti target, TiAl target (atomic ratio 5:5), TiSi target (atomic ratio 85:15) and V target, with the arc current of each cathode target 101 being 90A, the current of each bend being 1.5A, the substrate negative bias voltage being set to 100V, the argon flow rate being 40sccm, and the nitrogen flow rate in the vacuum chamber 104 being linearly increased to 40 sccm within 5min, so that the gas pressure of the mixed gas in the vacuum chamber 104 is 0.7 Pa, and the deposition time is 120 minutes.

[0036] An ultra-hard and high-toughness nanocomposite coating of Example 1 is prepared by the preparation method of an ultra-hard and high-toughness nanocomposite coating described in Example 1, wherein the transition layer 202 is sandwiched between the substrate 201 and the TiAlSiVN nanocomposite coating 203. The thickness of the TiAlSiVN nanocomposite coating 203 is 5.8 μm; The TiAlSiVN nanocomposite coating 203 comprises the following elements by mass percentage: 5.5% Al, 3.2% Si, 8.6% V, 45.1% N, and the balance Ti.

[0037] Example 2 A method for preparing an ultra-hard and highly tough nanocomposite coating includes the following steps performed sequentially: 1) Prepare substrate 201 and pre-clean it; 2) Perform glow discharge cleaning and ion cleaning on substrate 201; 3) A transition layer 202 is deposited on the substrate 201 using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating 203 was deposited on the transition layer 202 using a magnetically filtered vacuum cathode arc co-deposition method; In step 1), the pre-cleaning specifically includes: ultrasonically cleaning the substrate 201 with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the surface of the substrate 201. The substrate 201 is 316L stainless steel; In step 2), the glow discharge cleaning and ion cleaning specifically include: after completing the pre-cleaning, the substrate 201 is placed in the vacuum chamber 104 and mounted on the sample stage. After evacuating to below 0.005 Pa, argon gas is introduced with a flow rate of 60 sccm. The working pressure of the vacuum chamber 104 is 0.8 Pa, the starting negative bias voltage is 400 V, and glow discharge cleaning is started for 20 min. Then start the Ti target, with an arc current of 110A and a bending current of 1.5A. Adjust the negative bias voltage to 800V for ion cleaning, and the ion cleaning time is 10 minutes. In step 3), the preparation method of the transition layer 202 specifically includes: using a TiAl cathode target, introducing argon gas with a flow rate of 60 sccm into the vacuum chamber 104, the working gas pressure being 0.8 Pa, the arc current of the cathode target 101 being 100A, the bending current being 2A, the negative bias being 50V, and depositing a TiAl transition layer on the surface of the substrate 201 with a thickness of 0.3 μm; The cathode target 101 is a TiAl target, and a TiAl transition layer is deposited on the surface of the substrate 201 accordingly; In step 4), the preparation method of TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, with an arc current of 80 A for each cathode target 101, a current of 2 A for each bend, a substrate negative bias voltage of 100 V, an argon flow rate of 50 sccm, and a linear increase in the nitrogen flow rate in the vacuum chamber 104 to 30 sccm within 5 min, so that the pressure of the mixed gas in the vacuum chamber 104 is 1.1 Pa, and the deposition time is 120 min; In step 4), the four-channel magnetic filter vacuum cathode arc target uses Ti target, TiSi target (atomic ratio 85:15), V target and TiAl target (atomic ratio 5:5).

[0038] An ultra-hard and high-toughness nanocomposite coating of Example 2 is prepared by the preparation method of an ultra-hard and high-toughness nanocomposite coating described in Example 2, wherein the transition layer 202 is sandwiched between the substrate 201 and the TiAlSiVN nanocomposite coating 203. The thickness of the TiAlSiVN nanocomposite coating 203 is 6.4 μm; The TiAlSiVN nanocomposite coating 203 comprises the following elements by mass percentage: 6.1% Al, 3.9% Si, 9.2% V, 45.3% N, and the balance Ti.

[0039] Example 3 A method for preparing an ultra-hard and highly tough nanocomposite coating includes the following steps performed sequentially: 1) Prepare substrate 201 and pre-clean it; 2) Perform glow discharge cleaning and ion cleaning on substrate 201; 3) A transition layer 202 is deposited on the substrate 201 using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating 203 was deposited on the transition layer 202 using a magnetically filtered vacuum cathode arc co-deposition method; In step 1), the pre-cleaning specifically includes: ultrasonically cleaning the substrate 201 with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the surface of the substrate 201. The substrate 201 is 316L stainless steel; In step 2), the glow discharge cleaning and ion cleaning specifically include: after completing the pre-cleaning, the substrate 201 is placed in the vacuum chamber 104 and mounted on the sample stage. After evacuating to below 0.005 Pa, argon gas is introduced with a flow rate of 100 sccm. The working pressure of the vacuum chamber 104 is 1.2 Pa, the starting negative bias voltage is 400 V, and glow discharge cleaning is started for 20 min. Then start the Ti target, with an arc current of 70-130A, a bending current of 1.5A, and adjust the negative bias to 800V for ion cleaning. The ion cleaning time is 10 minutes. In step 3), the preparation method of the transition layer 202 specifically includes: using a cathode target 101, introducing argon gas with a flow rate of 120 sccm into the vacuum chamber 104, the working gas pressure being 1.1 Pa, the arc current of the cathode target 101 being 80 A, the bending current being 2.0 A, the negative bias being 50 V, and depositing the transition layer 202 on the surface of the substrate 201, wherein the thickness of the transition layer 202 is 0.3 μm; The cathode target 101 is a pure V target, and a corresponding V transition layer is deposited on the surface of the substrate 201. In step 4), the preparation method of the TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, the arc current of each cathode target 101 is 90A for Ti target and TiSi target, 110A for V target and TiAl target, the current of each bend is 2A, the substrate negative bias voltage is set to -100 V, the argon flow rate is 60 sccm, the nitrogen flow rate in the vacuum chamber 104 is linearly increased to 50 sccm within 5 min, so that the gas pressure of the mixed gas in the vacuum chamber 104 is 1.3 Pa, and the deposition time is 120 minutes; In step 4), the four-channel magnetic filter vacuum cathode arc target uses Ti target, TiSi target (atomic ratio 85:15), V target and TiAl target (atomic ratio 5:5).

[0040] An ultra-hard and high-toughness nanocomposite coating of Example 3 is prepared by the preparation method of an ultra-hard and high-toughness nanocomposite coating described in Example 3, wherein the transition layer 202 is sandwiched between the substrate 201 and the TiAlSiVN nanocomposite coating 203. The thickness of the TiAlSiVN nanocomposite coating 203 is 6.8 μm; The TiAlSiVN nanocomposite coating 203 comprises the following elements by mass percentage: 5.9% Al, 3.7% Si, 8.6% V, 46.3% N, and the balance Ti.

[0041] Table 1 Performance test data of the coatings prepared in the examples serial number transition layer thickness / μm TiAlSiVN nanocomposite coating thickness / μm The nanohardness of the TiAlSiVN nanocomposite coating (GPa) <![CDATA[Fracture toughness of TiAlSiVN nanocomposite coatings / MPa·m 1 / 2 > Example 1 0.4 5.8 40.2 3.8 Example 2 0.3 6.4 44.6 3.4 Example 3 0.3 6.8 41.1 3.35 The data in Table 1 show that the composite coating prepared in this invention has a hardness of 44.6 GPa and a fracture toughness of 3.35 MPa·m. 1 / 2 In addition, it possesses both extremely high hardness and extremely high toughness, solving the problem that it is difficult to improve the toughness of existing superhard coatings, and effectively improving the protective performance of the coating surface.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an ultra-hard and highly tough nanocomposite coating, characterized in that, The following steps are performed sequentially: 1) Prepare the substrate by pre-cleaning it; 2) Perform glow discharge cleaning and ion cleaning on the substrate; 3) A transition layer is deposited on the substrate using a magnetically filtered vacuum cathode arc co-deposition method; 4) A TiAlSiVN nanocomposite coating is deposited on the transition layer using a magnetically filtered vacuum cathode arc co-deposition method.

2. The method for preparing an ultra-hard and high-toughness nanocomposite coating according to claim 1, characterized in that, In step 1), the pre-cleaning specifically includes: ultrasonically cleaning the substrate with alcohol, acetone and deionized water for 15 minutes each to remove impurities or dirt from the substrate surface. The substrate is stainless steel, high-speed steel, or hard alloy.

3. The method for preparing an ultra-hard and high-toughness nanocomposite coating according to claim 1, characterized in that, In step 2), the glow discharge cleaning and ion cleaning specifically include: after completing the pre-cleaning, the substrate is placed in the vacuum chamber and mounted on the sample stage. After evacuating to below 0.005 Pa, argon gas is introduced. The argon gas flow rate is 20-200 sccm, the working pressure of the vacuum chamber is 0.3-2.0 Pa, the starting negative bias voltage is 200-600 V, and the glow discharge cleaning is started for 10-20 min. Then start the Ti target, with an arc current of 70-130A and a bending current of 1.5-3A. Adjust the negative bias voltage to 400-800V for ion cleaning, and the ion cleaning time is 5-30 minutes.

4. The method for preparing an ultra-hard and high-toughness nanocomposite coating according to claim 1, characterized in that, In step 3), the method for preparing the transition layer specifically includes: using a cathode target, introducing argon gas with a flow rate of 10-200 sccm into the vacuum chamber, the working gas pressure being 0.3-2.0 Pa, the arc current of the cathode target being 70-130 A, the bending current being 1.5-3 A, the negative bias being 50-200 V, and depositing a transition layer on the surface of the substrate, wherein the thickness of the transition layer is 0.1-0.5 μm; The cathode target is a pure Ti target, a pure V target, a TiAl target, or a TiAlSi target, and a Ti transition layer, a V transition layer, a TiAl transition layer, or a TiAlSi transition layer is deposited on the substrate surface accordingly.

5. The method for preparing an ultra-hard and highly tough nanocomposite coating according to claim 1, characterized in that, In step 4), the preparation method of TiAlSiVN nanocomposite coating specifically includes: using a four-channel magnetic filter vacuum cathode arc deposition method, with the arc current of each cathode target being 70-130A, the current of each bend being 1.5-3A, the substrate negative bias voltage being set to 0-200 V, the argon flow rate being 10-150 sccm, and the nitrogen flow rate in the vacuum chamber being linearly increased to 30-50 sccm within 5 min, so that the gas pressure of the mixed gas in the vacuum chamber is 0.5-3.0 Pa, and the deposition time is 120 minutes; The four types of cathode targets in the four channels aim to achieve the TiAlSiV combination. Elemental Si is not selected as the target material alone. Ti, Al and V elements are combined to form unary, binary or ternary alloys as cathode targets.

6. The method for preparing an ultra-hard and high-toughness nanocomposite coating according to claim 5, characterized in that, In step 4), the four-channel magnetic filter vacuum cathode arc target uses Ti target, TiSi target, V target and Al target respectively.

7. A superhard and highly tough nanocomposite coating, characterized in that, The coating is prepared by any one of the methods described in claims 1-6, wherein the transition layer is sandwiched between the substrate and the TiAlSiVN nanocomposite coating. The thickness of the TiAlSiVN nanocomposite coating is 5μm-8μm; The TiAlSiVN nanocomposite coating comprises the following elements by mass percentage: 5%-8% Al, 3%-5% Si, 8%-10% V, 45%-55% N, and the balance Ti.

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