Method for preparing titanium-carbon nano multilayer composite coating with interface fusion characteristic

Abstract

The invention belongs to the technical field of artificial joint preparation, and particularly relates to a method for preparing a titanium-carbon nano multilayer composite coating with an interface fusion characteristic. The method comprises the steps that S01, titanium alloy for 3D printing is prepared to serve as a base material; s02, alternately preparing Ti-TiN layers with the interface fusion characteristic by adopting cathode arc ion plating and anode layer ion beams, wherein the number of the Ti-TiN layers is not less than 5; and S03, preparing the amorphous carbon lubricating layer. The preparation method provided by the invention is mainly realized by changing the gas flow on the premise of setting constant current. No obvious interface structure exists between the prepared TiN layer and Ti layer, and the whole TiN-Ti layer is of a continuous structure; the structure has the good energy absorption characteristic, and the stress cracking and falling phenomena of the coating under the impact working condition can be relieved.

Description

[0001] Priority application This application claims priority to the Chinese invention patent application [CN202311707996.5] "A wear-resistant coating on the surface of titanium alloy artificial joint and its preparation method" filed on December 12, 2023, which is incorporated by reference in its entirety.

[0002] Divisional application This application is a divisional application based on the Chinese invention patent application with application number CN202411823012.4, application date December 11, 2024, and invention name “A method for preparing titanium-carbon nano-multilayer composite wear-resistant coating material on the surface of artificial joints”. Technical Field

[0003] The present invention belongs to the technical field of artificial joint preparation, and in particular relates to a method for preparing a titanium-carbon nano multilayer composite coating with interface fusion characteristics. Background Art

[0004] The unique internal environment of the human body places fundamental demands on artificial joint materials, including: (1) excellent biocompatibility; (2) good biomechanical compatibility; (3) excellent biocompatibility and stability; and (4) a long service life. However, the various types of artificial joints currently in use generally suffer from problems such as wear, loosening, dislocation, displacement, and sharp friction noise.

[0005] 3D-printed custom joints offer a new opportunity to address the shortcomings of traditional prosthetic methods, such as the difficulty in molding complex, modified joints and the inability to produce personalized products. Titanium alloy's superior strength-to-weight ratio and excellent biocompatibility have enabled progress in the clinical application of personalized all-titanium joints. However, titanium alloy's inherently poor shear strength makes it susceptible to rapid wear under bio-corrosion conditions when used as a friction interface material in joints, seriously impacting the long-term safety of implanted prostheses.

[0006] The patent with publication number CN101090743A and invention name "Prosthetic joint with joint surface layer including ADLC" discloses a prosthetic joint with a surface protective coating material, the surface of which has amorphous diamond-like carbon (ADLC). The patented technology proposes to set a bonding layer between the base layer and the surface layer ADLC, including (base)-Ti-TiN-Ti-TiN. Those skilled in the art generally believe that the performance of the bonding layer is crucial to the performance of the overall coating. However, the patent does not disclose a clear and feasible method for preparing the bonding layer, and the performance comparison effect in the patent examples is even more unclear. Therefore, the patent only proposes a structural design for a prosthetic joint. The research on the design and performance comparison of surface protective coating materials is not in-depth enough, and no effective surface modification technology solution is proposed.

[0007] Currently, there are two common approaches to strengthening the friction interface of 3D-printed titanium alloy artificial joints: 1) Printing a set of friction components made of cobalt-chromium-molybdenum alloy separately and assembling them into the prosthesis. This approach uses cobalt-chromium-molybdenum, a traditional implant material, to improve the biological and tribological properties of the friction interface, thereby extending the lifespan of the joint. However, this approach suffers from the long production and design cycle and high costs of joint prostheses. More importantly, the separate printing and integrated assembly method also leads to multiple dissimilar metal contact interfaces within the prosthesis. These interfaces can cause problems such as galvanic corrosion and fretting during use, hindering the full potential of 3D printing in the design and processing of personalized joint prostheses and even potentially introducing other hazards. 2) Developing high-strength, wear-resistant coatings on titanium alloy surfaces to extend the lifespan of joint prostheses. This approach uses surface engineering techniques to create a wear-resistant, high-hardness protective coating on the prosthesis surface. Physical vapor deposition (PVD) is typically used for this purpose, but this method often places high demands on the material system and process precision, requiring precise control of both the composition and structure of the coating to achieve high-performance coatings.

[0008] In summary, it is necessary to propose new specific feasible methods and strategies to alleviate the shortcomings of existing technologies. Summary of the Invention

[0009] The purpose of the present invention is to provide a method for preparing a titanium-carbon nano-multilayer composite coating with interfacial fusion characteristics, which partially solves or alleviates the above-mentioned deficiencies in the prior art. The present invention specifically adopts the following technical solutions.

[0010] One aspect of the present invention provides a preparation method.

[0011] A method for preparing a titanium-carbon nano-multilayer composite coating having interfacial fusion characteristics comprises the following steps: S010: Prepare a titanium alloy for 3D printing as a base material, place the base material on the equipment sample holder, and rotate the sample holder to the front of the anode layer linear ion beam. Let argon (Ar) flow into the anode layer linear ion beam to ionize it, and pre-treat (etch) the base material to remove the surface oxide film; S020: Alternately preparing a Ti-TiN layer having an interface fusion characteristic by using cathodic arc ion plating and anodic layer ion beam, wherein the thickness of the prepared Ti-TiN layer is set to be 1.6-3.0 μm, and the number of the Ti-TiN layer is not less than 5 layers (i.e., at least 5 layers); S021: setting a constant current, setting the cathode arc target current to 70A; setting the argon gas flow rate to f1, and the deposition time on the substrate to t1 to prepare a Ti layer; S022: setting a constant current and a cathode arc target current of 70A; setting a nitrogen flow rate of f2, and depositing a TiN layer on the Ti layer for a time of t2; then reducing the nitrogen flow rate to f3 / min and introducing argon at a rate of f4 / min, gradually changing the two gases to allow the TiN layer to transition to the Ti layer, and the duration is t3; S023: Set a constant current and the cathode arc target current to 70A; set the argon flow rate to f1 and the deposition time to t4 to prepare a Ti layer; reduce the argon flow rate at a rate of f4 / min and increase the nitrogen flow rate at a rate of f3 / min, and gradually change the two gases to make the Ti layer transition to the TiN layer (until the TiN layer is prepared), and the duration is t5; Among them, the air flow velocity f3 / min is greater than the air flow velocity f4 / min; The argon flow rate f1 is 200 sccm; the deposition time t1 is 20 minutes; the nitrogen flow rate f2 is 450 sccm; the deposition time t2 is 5-20 minutes; the gas flow rate f3 / min is 45-90 sccm / min; the time t3 is 5-10 minutes; the gas flow rate f4 / min is 20-40 sccm / min; the time t4 is 5-10 minutes; and the time t5 is 5-10 minutes. Repeat S022-S023, so that the last layer prepared is a Ti layer; S030: The sample holder is rotated to the front of the anode layer ion beam, and a constant current is set, and the ion beam current is set to 0.2 A; the C2H2 gas flow rate is set to 40-50 sccm, and the deposition is performed for 30-40 minutes to prepare an amorphous carbon (DLC) lubricating layer.

[0012] Those skilled in the art will understand that, based on specific needs, by adjusting the air flow rate and deposition time of f3 / min and f4 / min within the scope defined by the present invention, a Ti-TiN layer greater than 5 layers can be prepared.

[0013] Amorphous carbon materials have high hardness, high biosafety and excellent wear resistance, and are excellent lubricating coating materials. However, due to their high hardness, the difference between their own mechanical properties and the mechanical properties of the metal matrix is ​​too large, and it is easy to cause peeling and splitting caused by the mismatch of mechanical properties. Therefore, one of the focuses of the method of the present invention is to design a bonding layer material with good support and toughness for the top amorphous carbon lubricating layer. The bonding layer material has moderate hardness and plays a good supporting role between the bottom metal base layer and the top amorphous carbon layer. At the same time, it can absorb instantaneous impact energy, thereby improving the overall performance of the entire composite material.

[0014] Furthermore, the prepared Ti-TiN layer has a continuous structure.

[0015] Furthermore, when pre-treating the substrate material, a constant current is set, and the argon gas flow rate is set to 40-50 sccm; the equipment cavity temperature is set to no less than 200° C., and the cavity pressure is kept constant at 2.0 mTorr by adjusting the gas flow; and the deposition time is 20-30 minutes.

[0016] As a preference, the temperature of the equipment cavity is set to 200°C.

[0017] Furthermore, in S021, the temperature of the equipment cavity is set to no less than 200° C., and the pressure of the cavity is set to 40-50 mTorr.

[0018] As a preference, the chamber temperature of the device is set to 200-230° C.; and the chamber pressure is set to 45 mTorr.

[0019] Furthermore, in S022, the temperature of the equipment cavity is set to no less than 200° C., the pressure of the cavity is set to 40-50 mTorr, and the time t2 is 5 minutes.

[0020] As a preference, the chamber temperature of the device is set to 200-230° C.; and the chamber pressure is set to 45 mTorr.

[0021] Furthermore, in S022, the nitrogen introduction rate f3 / min is reduced to 90 sccm / min, the argon introduction rate f4 / min is set to 40 sccm / min, and the time t3 is 5 minutes.

[0022] Furthermore, the time t4 is 10 minutes; the time t5 is 10 minutes.

[0023] As a preference, the thickness of the prepared Ti-TiN layer is set to 1.6 μm, and the number of Ti-TiN layers is 5 (Ti:TiN=5:5).

[0024] As a preference, when pre-treating the substrate material, the constant current is set to 0.2 A, the argon gas flow rate is set to 48-50 sccm, and the deposition time is 30 minutes.

[0025] As a preference, the C2H2 gas flow rate in S030 is set to 48-50 sccm, and the cavity pressure is kept constant at 2.0 mTorr by adjusting the gas flow.

[0026] Another aspect of the present invention provides a product prepared by the above preparation method.

[0027] The titanium-carbon nano-multilayer composite coating with interfacial fusion characteristics prepared by the above preparation method is composed, from bottom to top, of a substrate material, an intermediate energy absorption layer, and a top amorphous carbon lubricating layer; the intermediate energy absorption layer is a continuous Ti-TiN layer with interfacial fusion characteristics. Alternatively, the titanium-carbon nano-multilayer composite coating is provided with alternately deposited Ti-TiN layers with interfacial fusion characteristics as the intermediate energy absorption layer.

[0028] Preferably, the thickness of the intermediate energy absorption layer is 1.6-3.0 μm, and the number of layers is not less than 5.

[0029] Furthermore, a Ti layer serves as a bonding layer between the base material and the intermediate energy absorption layer; and a Ti layer serves as a bonding layer between the top amorphous carbon lubricating layer and the intermediate energy absorption layer. In other words, the intermediate energy absorption layer has a Ti-TiN-Ti-TiN-Ti-structure with interfacial fusion characteristics.

[0030] Furthermore, the overall thickness of the titanium-carbon nano multilayer composite coating with interface fusion characteristics is 3-3.5 μm.

[0031] The present invention can also provide the application of the preparation method and the product.

[0032] Application of the above preparation method in the preparation of artificial wear-resistant joints.

[0033] The application of the above titanium-carbon nano multilayer composite coating in the preparation of artificial wear-resistant joints.

[0034] Beneficial technical effects: It is unacceptable for artificial joint surface protective coating materials to prematurely peel and fail during service under the friction-corrosion coupling effect in the human body. The fundamental cause of this peeling failure is the coating's excessive internal stress and insufficient bonding strength with the substrate. Based on this, the present invention proposes a composite structure that integrates a strengthened substrate surface bonding layer, an intermediate energy absorption layer with an interface fusion structure, and a top lubricating layer. This approach, combined with an alternating gradient arc ion plating technique, successfully produces a titanium-carbon composite protective coating material with multi-layer interface fusion characteristics. The specific technical solution is as follows.

[0035] First, a high-ionization-rate, high-ion-energy arc ion plating technique was proposed. A metallurgically bondable Ti layer was first deposited on the surface of the artificial joint prosthesis as a bonding layer to improve the overall coating's bonding properties. Subsequently, a TiN-Ti layer with interfacial fusion properties was periodically deposited on the surface as an energy-absorbing layer to reduce the coating's internal stresses. This effectively mitigates stress cracking during frictional impact, thereby preventing the coating from brittle fracture and spalling under impact. The TiN-Ti interfacial fusion layer was chosen for the following reasons: the Ti layer is relatively soft, with mechanical properties comparable to those of the substrate, while the TiN layer is extremely hard, making it a hard ceramic layer. By gradually and periodically varying the flow of Ar-N₂ reactant gas during the deposition process, a TiN-Ti interfacial fusion layer structure was achieved. This structure lacks a distinct interlayer interface but exhibits a unique alternating structure of soft (Ti layer) and hard (TiN). This structure effectively absorbs and releases stress transmitted from the joint surface during transient impacts (such as those experienced by jumping or running), preventing the formation of through-cracks and subsequent failure of the coating. Finally, a smooth, dense amorphous carbon layer is deposited on top of the multilayer structure using anodic ion beam deposition (AIBD) technology as a top lubricating layer. The present invention specifically proposes creating a variety of materials with interfacial fusion and alternating Ti-TiN layers by varying the deposition time within a specific thickness range. The multilayer structure material with the best overall performance was then screened.

[0036] The present invention proposes a method for preparing a titanium-carbon nano-multilayer composite coating with interfacial fusion characteristics. The preparation method is mainly achieved by changing the gas flow rate under the premise of setting a constant current. There is no obvious interface structure between the TiN layer and the Ti layer prepared by the present invention with interfacial fusion characteristics, and the entire TiN-Ti layer is a continuous structure; this structure has good energy absorption characteristics and can slow down the stress cracking and shedding phenomenon of the coating under impact conditions. Experiments have found that when the prepared TiN-Ti layer is 5 layers, its friction performance and mechanical properties are significantly better than those of a coating with less than 5 layers.

[0037] Compared with other wear-resistant coating preparation technologies, the alternating gradient arc ion plating technology proposed in the present invention has a large design range and high process controllability for the composite structure coating material. The prepared coating material can be used as the final product instead of using other additional processing (such as polishing) processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the various elements or parts are not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work.

[0039] Figure 1 Schematic diagram of the vacuum coating equipment used in the present invention (the left side shows the cathode arc target, where the Ti and TiN layers are formed by controlling the type of gas introduced; the right side shows the anode layer ion source, where acetylene is introduced to form the top amorphous carbon layer); Figure 2 Schematic diagram of the structure of the titanium-carbon multilayer coating prepared in Example 1 of the present invention (intermediate layer Ti:TiN=5:5); Figure 3 Schematic diagram of the structure of the titanium-carbon multilayer coating prepared in Example 2 of the present invention (intermediate layer Ti:TiN=3:3); Figure 4 Schematic diagram of the structure of the titanium-carbon multilayer coating prepared in Example 3 of the present invention (intermediate layer Ti:TiN=1:1); Figure 5 Schematic diagram of the structure of a Ti-TiN multilayer coating without a top amorphous carbon layer prepared in Example 4 of the present invention (Ti:TiN=4:4); Figure 6 The cross-sectional structural morphology and energy line scanning results of the Ti / TiN / amorphous carbon multilayer coating with interface fusion characteristics prepared in Example 2 of the present invention; Figure 7 The cross-sectional structural morphology and NEP scanning results of the Ti / TiN / amorphous carbon multilayer coating with interface fusion characteristics prepared in Example 3 of the present invention; Figure 8 The cross-section and surface structure morphology of the Ti / TiN multilayer coating prepared in Example 4 of the present invention; Figure 9 Tribological curves and wear rate results of coating samples and 3D-printed titanium alloy substrates prepared in different embodiments of the present invention when rubbed against polytetrafluoroethylene materials; Figure 10 This is a bonding strength test of the titanium-carbon multilayer coating prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] As used herein, "and / or" includes any and all combinations of one or more of the associated listed items.

[0042] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0043] As used in this specification, the term "about" typically means + / - 5% of the stated value, more typically + / - 4% of the stated value, more typically + / - 3% of the stated value, more typically + / - 2% of the stated value, even more typically + / - 1% of the stated value, and even more typically + / - 0.5% of the stated value.

[0044] In this specification, certain embodiments may be disclosed in a format that is within a range. It should be understood that this description of "within a range" is merely for convenience and brevity and should not be interpreted as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within this range. For example, the description of a range of 1-6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. Regardless of the breadth of the range, the above rules apply.

[0045] The “interface fusion characteristics” mentioned in the present invention refer to the fact that there is no obvious interface structure between the prepared TiN layer and the Ti layer, and the contrast difference between the two has a gradual characteristic.

[0046] The titanium-carbon composite layer prepared by the present invention has the following characteristics.

[0047] Good hardness: The intermediate layer Ti / TN coating has a very high hardness, usually between 2000-3000HV, which is higher than the hardness of many metal and non-metallic materials. By regulating the ratio and interface structure of the two, a combination of good hardness and toughness can be achieved.

[0048] Good wear resistance: Due to its high hardness, titanium nitride coatings have excellent wear resistance and can significantly extend the service life of the substrate.

[0049] Good corrosion resistance: Titanium nitride coatings exhibit excellent corrosion resistance in many corrosive media, helping to protect the substrate from corrosion.

[0050] Amorphous carbon coating: Amorphous carbon is a type of solid lubricating coating material that exhibits high hardness (amorphous carbon coatings produced using PVD technology can reach hardnesses exceeding 40 GPa), excellent chemical stability (no chemical corrosion in any solution), and self-lubricating properties. It has important applications in the aerospace field. In Example 4 of the present invention, the friction coefficient of the sample without a top amorphous carbon coating was approximately 0.4, significantly higher than the friction coefficient of approximately 0.1-0.2 for the samples with amorphous carbon coating (Examples 1-3), demonstrating the self-lubricating properties of the amorphous carbon coating.

[0051] Example 1 This embodiment provides a multi-layer titanium-carbon composite coating material. Figure 1 The vacuum coating equipment shown in FIG. 1 is used. The coating structure prepared in this embodiment is as follows Figure 2 As shown, the specific preparation process is as follows.

[0052] 1. Preparation of substrate materials The 3D-printed titanium alloy substrate was polished before coating. The substrate measured 17 mm × 17 mm × 3 mm. Before coating deposition, the 3D-printed, polished titanium alloy substrate was ultrasonically cleaned in anhydrous ethanol and acetone for 15 minutes each to remove surface oil and other impurities. Any remaining liquid was then dried with a hair dryer before use.

[0053] 2. Pretreatment of substrate materials Sample clamping. Place the pre-treated 3D printed titanium alloy substrate on the sample holder and use a special clamp to fix the sample firmly on the sample holder and ensure good electrical conductivity with the sample holder. After placing the sample holder in the coating chamber of the equipment, the chamber is evacuated using a mechanical pump and a molecular pump to control the chamber pressure to be less than 2.0×10 -5 Torr, the sample is pretreated before coating (i.e., sample etching pretreatment).

[0054] Sample etching pretreatment. After the vacuum degree of the vacuum chamber reaches the set value, open the chamber and heat it to 200℃. After the temperature reaches the set value, start etching. Argon is introduced into the linear ion beam of the anode layer and ionized. +Ions etch and clean the surface of the substrate material to remove the oxide film formed on the sample surface in the air, thereby increasing the bonding strength between the subsequent coating material and the substrate material. The specific treatment process is as follows: Ion beam set current: 0.2 A; Ar gas flow rate: 48-50 sccm, the chamber pressure was kept constant at 2.0 mTorr by adjusting the gas flow, and the output power was 120 W; Substrate negative bias: -100 V; Etching time: 30 min.

[0055] 3. Preparation of intermediate energy absorption layer (coating) Ti layer (bonding layer): Set the cathodic arc target current to 70 A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, and the chamber temperature to 200°C-230°C. Deposition time: 20 minutes (t1).

[0056] TiN layer: Set the cathodic arc target current to 70A, the nitrogen flow rate to 450 sccm (f2), the chamber pressure to 45 mTorr, the substrate negative bias to -60 V, and the chamber temperature to 200°C-230°C. First, deposit a pure TiN layer for 5 minutes (t2). Then, over 5 minutes (t3), nitrogen flow was reduced at 90 sccm / min (f3) and argon flowed at 40 sccm / min (f4). By gradually alternating the two gases, while ensuring stable target discharge, interfacial fusion of the TiN-Ti layer was achieved. The total duration was 10 minutes.

[0057] Ti layer: Set the cathodic arc target current to 70A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, the chamber temperature to 200°C-230°C, and the deposition time to 10 minutes (t4). Subsequently, the argon flow was reduced at a rate of 40 sccm / min (f4), and nitrogen was gradually introduced at a rate of 90 sccm / min (f3), gradually transitioning from a pure Ti layer to a pure TiN layer. The deposition duration was 10 minutes (t5).

[0058] Repeat the above steps.

[0059] Top amorphous carbon layer: Rotate the sample holder to the front of the anode layer ion beam by revolution, set the ion beam current to 0.2 A, C2H2 gas flow rate: 48-50 sccm, maintain the chamber pressure constant at 2.0 mTorr by adjusting the gas flow, output power 120 W, substrate negative bias: -100 V, and deposition time 30 minutes.

[0060] Through the above preparation process, a composite coating structure with a Ti bonding layer, a Ti-TiN intermediate layer with a 5-periodic interface fusion structure, and a top amorphous carbon lubricating layer is finally achieved.

[0061] In this embodiment, a Ti bonding layer with a thickness of 0.6 μm (multiplied by 2) is prepared, the thickness of the alternating TiN-Ti layer in the middle is 1.6 μm, and the thickness of the top layer is 0.5 μm, for a total thickness of about 3.3 μm.

[0062] Example 2 This embodiment provides another example of a titanium-carbon composite coating material.

[0063] The preparation and pretreatment of the substrate materials involved in the preparation process used in this embodiment are the same as those in Example 2, except that the number of intermediate layers and the deposition time are different. The structure of the prepared coating is as follows: Figure 3 shown.

[0064] The intermediate energy absorbing layer (coating) is prepared as follows: Ti layer (bonding layer): Set the cathodic arc target current to 70 A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, and the chamber temperature to 200°C-230°C. Deposition time: 20 minutes (t1).

[0065] TiN layer: Set the cathodic arc target current to 70A, the nitrogen flow rate to 450 sccm (f2), the chamber pressure to 45 mTorr, the substrate negative bias to -60 V, and the chamber temperature to 200°C-230°C. First, deposit a pure TiN layer for 10 minutes (t2). Then, over 10 minutes (t3), reduce the nitrogen flow rate to 45 sccm / min (f3) and introduce argon at 20 sccm / min (f4). By gradually alternating the two gases, while ensuring stable target discharge, interfacial fusion of the TiN-Ti layer is achieved. The total duration is 20 minutes.

[0066] Ti layer: Set the cathode arc target current to 70A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, the chamber temperature to 200°C-230°C, and the deposition time to 10 minutes (t4). Then, over 10 minutes (t5), the argon flow rate was reduced at a rate of 20 sccm / min (f4), and nitrogen was gradually introduced at a rate of 45 sccm / min (f3), gradually transitioning from a pure Ti layer to a pure TiN layer.

[0067] Taking Ti-TiN as one deposition cycle, a total of 3 deposition cycles were performed to obtain the following Figure 3 The structure shown has three periodic structure intermediate layers.

[0068] Top amorphous carbon layer: Rotate the sample holder to the front of the anode layer ion beam by revolution, set the ion beam current to 0.2 A, C2H2 gas flow rate: 48-50 sccm, maintain the chamber pressure constant at 2.0 mTorr by adjusting the gas flow, output power 120 W, substrate negative bias: -100 V, and deposition time 30 minutes.

[0069] In this embodiment, a Ti bonding layer with a thickness of 0.6 μm (multiplied by 2) is prepared, the thickness of the alternating TiN-Ti layer in the middle is 1.6 μm, and the thickness of the top layer is 0.5 μm, for a total thickness of about 3.3 μm.

[0070] Example 3 This embodiment provides another improved example of preparing titanium nitride coating materials based on embodiment 3.

[0071] The preparation and pretreatment of the substrate materials involved in the preparation process used in this embodiment are the same as those in Example 3, with the difference being the number of intermediate layers and the deposition time. The structure of the prepared coating is as follows: Figure 4 shown.

[0072] Optimize process parameters: Ti layer (bonding layer): Set the cathodic arc target current to 70 A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, and the chamber temperature to 200°C-230°C. Deposition time: 20 minutes (t1).

[0073] TiN layer: A pure TiN layer was deposited for 20 minutes (t2) using a cathodic arc target current of 70A, a nitrogen flow rate of 450 sccm (f2), a chamber pressure of 45 mTorr, a negative substrate bias of -60 V, and a chamber temperature of 200°C-230°C. The process then reduced the nitrogen flow rate to 45 sccm / min (f3) over 10 minutes (t3), and introduced argon at 20 sccm / min (f4). By gradually alternating the two gases, while ensuring stable target discharge, interfacial fusion of the TiN-Ti layer was achieved. The total duration was 30 minutes.

[0074] Ti layer: Set the cathode arc target current to 70A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias voltage to -60 V, the chamber temperature to 200°C-230°C, and the deposition time to 10 minutes (t4). Subsequently, the argon flow rate was reduced at a rate of 20 sccm / min (f4), and nitrogen was gradually introduced at a rate of 45 sccm / min (f3), gradually transitioning from a pure Ti layer to a pure TiN layer, which lasted for 10 minutes (t5).

[0075] Top amorphous carbon layer: ion beam current 0.2 A, C2H2 gas flow: 48-50 sccm, the chamber pressure was kept constant at 2.0 mTorr by adjusting the gas flow, output power 120 W, substrate negative bias: -100 V, and deposition time 30 minutes.

[0076] It can be understood that, with Ti-TiN as one deposition cycle, n deposition cycles can be performed as needed to prepare the titanium nitride coating material.

[0077] Example 4 This embodiment provides an example of device operation with a titanium nitride coating without a top amorphous carbon layer.

[0078] This embodiment proposes another example of preparing a titanium nitride coating material without a top amorphous carbon coating based on embodiment 1. The difference lies in the number of intermediate layers and the deposition time. The structure of the prepared coating is as follows: Figure 5 shown.

[0079] Ti layer: set the cathode arc target current to 70 A, the argon flow rate to 200 sccm (f1), the chamber pressure to 45 mTorr, the substrate negative bias to -60 V, the chamber temperature to 200°C-230°C, and the deposition time to 15 minutes (t1).

[0080] TiN layer: Set the cathode arc target current to 70A, the nitrogen flow rate to 450 sccm (f2), the chamber pressure to 45mTorr, the substrate negative bias voltage to -60 V, the chamber temperature to 200℃-230℃, and the deposition time to 13 minutes (t2).

[0081] The above Ti-TiN layer is regarded as one cycle, and a total of 4 cycles are deposited.

[0082] The top TiN layer has the same process parameters as the second TiN layer, but the deposition time is extended to 30 minutes to increase the thickness. This ultimately forms a nitrogen-based composite coating with an alternating Ti-TiN structure.

[0083] Example 5 This example provides performance tests of multiple coating materials prepared above.

[0084] 1. Friction coefficient The coating materials prepared in Examples 1-4 and the 3D printed titanium alloy substrate used were used as control test groups to conduct friction and wear performance tests. The friction coefficient and wear rate of the coatings obtained from the tests are shown in Tables 1 and Figure 9 .

[0085] Table 1 Friction coefficient From the results in Table 1, we can see that the friction coefficient and wear rate of the samples with composite coating (Examples 1-4) are significantly lower than those of the base titanium alloy material, indicating that the coating can indeed significantly reduce the wear of the base material. Figure 9 It can be seen intuitively that after the amorphous carbon layer is prepared on the top layer, the friction coefficient of the coating is lower than that of the sample with a TiN coating as the top layer. The amorphous carbon with lubricating effect prepared on the top layer of the surface can further reduce wear. Furthermore, from the trend of the friction coefficient curve, it can be seen that the friction coefficient of the titanium-carbon composite coating with an intermediate layer ratio of Ti:TiN=5:5 is the lowest, and the curve is smooth and flat with minimal fluctuations during the entire friction process, while the friction coefficient of the titanium-carbon composite coating with other intermediate layer ratios shows a gradual increase and obvious fluctuations. During these fluctuating surface friction processes, the intermediate layer of the coating cannot continue to provide a good stress absorption effect, resulting in localized instantaneous cracking of the coating, which will accelerate the failure of the coating. This shows that the multi-layer "interface fusion characteristics" structure can better absorb external stress. From the wear rate, it can be seen that the multi-layer titanium-carbon composite coating can reduce the wear rate by 2 orders of magnitude and significantly reduce the wear of the base material.

[0086] Judging from the indicators of the tribological properties of the above-mentioned coatings, the sample proposed in the present invention having a multi-layer titanium-carbon composite coating (intermediate layer ratio Ti:TiN=5:5) can significantly reduce substrate wear and inhibit coating peeling during long-term wear, thereby extending the service life of the coating.

[0087] 2. Coating structure characterization test Figure 6 This is a cross-sectional topography and line scan of a Ti / TiN / amorphous carbon multilayer coating with interfacial fusion, prepared in Example 1 of the present invention. As can be seen, there is no distinct interface between the darker portion (TiN layer) and the lighter portion (Ti layer), and the contrast between them exhibits a gradual gradient, indicating a fusion-like interface. The total coating thickness is approximately 3.3 μm, and the coating exhibits no defects such as interlayer cracking.

[0088] Figure 7 The cross-sectional structural morphology and energy spectrum line scan results of a Ti / TiN / amorphous carbon multilayer coating with interfacial fusion characteristics, prepared in Example 3 of the present invention, are shown. The SEM results of the coating cross section show a total coating thickness of approximately 3.4 μm, with an intact coating interface surface. The elemental surface distribution energy spectrum results reveal a clear compositional transition between the Ti-TiN layers, with a gradual contrast difference between the two layers, indicating a fusion interface structure.

[0089] Figure 8This SEM image shows a cross-section of a multilayer titanium nitride coating without a top amorphous carbon coating, prepared in Example 4 of the present invention. The image shows a multilayer structure with a total coating thickness of approximately 1.82 μm, including a 280 nm Ti layer and a 300 nm intermediate TiN layer. The coating's interface surface is intact, with no interlayer cracking. However, the overall coating surface is relatively rough, with numerous large particle defects, a drawback of conventional arc ion plating techniques. Furthermore, the compositional transition between the Ti and TiN layers is not distinct, indicating a lack of fusion at the interface.

[0090] 3. Coating mechanical properties test The mechanical properties of the coating were tested using nanoindentation testing technology, and the test results are shown in Table 2. By comparison, it was found that the hardness of the coatings in Examples 1-4 exceeded 13 GPa, which was significantly higher than the 3.5 GPa of the 3D printed titanium alloy substrate. This shows that the coating can significantly improve the hardness of the substrate titanium alloy. In addition, the hardness of the samples with a top layer of amorphous carbon coating (Examples 1-3) was higher than that of the sample without a top layer of amorphous carbon in Example 4. The more cycles with interface fusion characteristics in the multilayer structure, the lower the overall hardness of the sample, but the elastic modulus increased, and the toughness of the surface coating was improved, which will help the coating avoid brittle fracture and increase the overall service life of the coating.

[0091] Table 2 Mechanical properties test results of coating and substrate materials 4. Test of the bonding performance between coating and substrate Figure 10 The bonding strength of the titanium-carbon multilayer coating prepared in Example 1 of the present invention (intermediate layer Ti:TiN = 5:5) was tested. The results showed that the multilayer titanium-carbon composite coating, prepared using the alternating gradient arc ion plating technique, achieved a bonding strength of 32N, demonstrating excellent bonding performance. Typical amorphous carbon coatings have a bonding strength of approximately 20N.

[0092] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0093] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for preparing a titanium-carbon nano-multilayer composite coating with interfacial fusion characteristics, characterized in that: The following steps are involved: S010: Prepare a titanium alloy for 3D printing as a base material, place the base material on a sample holder of the equipment, and rotate the sample holder to the front of the linear ion beam of the anode layer. Let argon gas flow into the linear ion beam of the anode layer to ionize it, and pre-treat the base material to remove the surface oxide film. S020: Alternately preparing a Ti-TiN layer having an interface fusion characteristic by cathode arc ion plating and anode layer ion beam plating, wherein the thickness of the prepared Ti-TiN layer is set to be 1.6-3.0 μm, and the number of the Ti-TiN layer is not less than 5 layers; S021: setting a constant current, setting the cathode arc target current to 70A; setting the argon gas flow rate to f1, and the deposition time on the substrate to t1 to prepare a Ti layer; S022: Set constant current and cathode arc target current to 70A; The nitrogen flow rate is set to f2, and the deposition time on the Ti layer is t2 to prepare a TiN layer; then the nitrogen flow rate is reduced to f3 / min, and argon gas is introduced at a rate of f4 / min, and the TiN layer is transitioned to the Ti layer by gradually changing the two gases, and the duration is t3; S023: Set a constant current and the cathode arc target current to 70A; set the argon flow rate to f1 and the deposition time to t4 to prepare a Ti layer; reduce the argon flow rate at a rate of f4 / min and increase the nitrogen flow rate at a rate of f3 / min, and gradually change the two gases to make the Ti layer transition to the TiN layer, and the duration is t5; Among them, the air flow velocity f3 / min is greater than the air flow velocity f4 / min; The argon flow rate f1 is 200 sccm; the deposition time t1 is 20 minutes; the nitrogen flow rate f2 is 450 sccm; the deposition time t2 is 5-20 minutes; the gas flow rate f3 / min is 45-90 sccm / min; the time t3 is 5-10 minutes; the gas flow rate f4 / min is 20-40 sccm / min; the time t4 is 5-10 minutes; and the time t5 is 5-10 minutes. Repeat S022-S023, so that the last layer prepared is a Ti layer; S030: Rotate the sample holder to the front of the anode layer ion beam, set a constant current, set the ion beam current to 0.2A; set the C2H2 gas flow rate to 40-50 sccm, and deposit for 30-40 minutes to prepare an amorphous carbon lubricating layer.

2. The preparation method according to claim 1, wherein When pretreating the substrate material, a constant current is set, an argon gas flow rate is set to 40-50 sccm, the equipment cavity temperature is set to not less than 200° C., and the cavity pressure is kept constant at 2.0 mTorr by adjusting the gas flow; and the deposition time is 20-30 minutes.

3. The preparation method according to claim 1, wherein In the S021, the device cavity temperature is set to no less than 200° C., and the cavity pressure is set to 40-50 mTorr.

4. The preparation method according to claim 1, wherein In the step S022 , the temperature of the equipment cavity is set to no less than 200° C., the pressure of the cavity is set to 40-50 mTorr, and the time t2 is set to 5 minutes.

5. The preparation method according to claim 1, wherein In the S022, the nitrogen introduction rate f3 / min is reduced to 90 sccm / min, the argon introduction rate f4 / min is set to 40 sccm / min, and the time t3 is 5 minutes.

6. The preparation method according to claim 1, wherein The time t4 is 10 minutes; the time t5 is 10 minutes.

7. The preparation method according to claim 1, wherein The thickness of the prepared Ti-TiN layer is set to 1.6 μm, and the number of the Ti-TiN layers is 5.

8. The preparation method according to claim 2, wherein When pre-treating the substrate material, the constant current is set to 0.2 A, the argon gas flow rate is set to 48-50 sccm, and the deposition time is 30 minutes.

9. The preparation method according to claim 1, wherein In the S030, the C2H2 gas flow rate is set to 48-50 sccm, and the cavity pressure is kept constant at 2.0 mTorr by adjusting the gas flow.

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