Method for producing titanium-carbon nanolayered composite wear-resistant coating with interfacial fusion characteristics

Abstract

The present application belongs to the technical field of artificial joint preparation, and particularly relates to a method for preparing a titanium-carbon nanometer multilayer composite coating with interface fusion characteristics. The method comprises the following steps: S01, preparing a 3D printed titanium alloy as a base material; S02, alternately preparing a Ti-TiN layer with interface fusion characteristics by using cathode arc ion plating and anode layer ion beam, and the number of layers of the Ti-TiN layer is not less than 5 layers; and S03, preparing an amorphous carbon lubricating layer. The preparation method mainly realizes the change of gas flow under the premise of setting a constant current. There is no obvious interface structure between the prepared TiN layer and Ti layer, and the whole TiN-Ti layer is a continuous structure. The structure has good energy absorption characteristics, and can slow down the stress cracking and falling off phenomenon of the coating under impact working conditions.

Description

[0001] Priority Application

[0002] This application claims priority to Chinese Invention Patent Application No. CN202311707996.5, “A Wear-Resistant Coating for the Surface of a Titanium Alloy Artificial Joint and a Preparation Method,” filed on December 12, 2023, which is incorporated by reference in its entirety.

[0003] Divisional Application

[0004] This application is a divisional application of Chinese Invention Patent Application No. CN202411823012.4, filed on December 11, 2024, entitled “A Preparation Method for a Titanium-Carbon Nanometer Multilayer Composite Wear-Resistant Coating Material for the Surface of an Artificial Joint.” TECHNICAL FIELD

[0005] The present application belongs to the technical field of artificial joint preparation, and specifically relates to a method for preparing a titanium-carbon nanometer multilayer composite wear-resistant coating with interface fusion characteristics. BACKGROUND

[0006] The special human body environment puts forward the most basic requirements for artificial joint materials, including: (1) excellent biocompatibility; (2) good biomechanical compatibility; (3) excellent biological bonding performance and stability; (4) long service life. However, the currently used various types of artificial joints generally have problems such as easy wear, loosening, misplacement, deviation, sharp friction noise, etc.

[0007] 3D printing customized joints provide a new opportunity to solve the shortcomings of traditional forming methods (difficulty in forming complex modified joints, inability to produce individually, etc.). The good specific strength and excellent biocompatibility of titanium alloy enable the clinical application of individualized titanium joints to make progress. However, due to the poor shear strength of titanium alloy, it faces the problem of rapid wear under biological corrosion conditions when used as a joint friction interface material, which seriously affects the long-term safe use of implanted prostheses.

[0008] Patent with publication number CN101090743A and the invention name of "Artificial joint with joint surface layer including ADLC" discloses an artificial joint with surface protective coating material, and the artificial joint surface has amorphous diamond-like carbon (ADLC). The patent technology proposes to set a bonding layer between the base layer and the surface layer ADLC, including (base)-Ti-TiN-Ti-TiN. It is generally believed by those skilled in the art that the performance of the bonding layer is crucial to the performance of the overall coating, however, the patent does not disclose an explicit and operable method for preparing the bonding layer, and the performance comparison effect in the patent embodiment is also unclear. Therefore, the patent only proposes a structural design of the artificial joint. The design and performance comparison of the surface protective coating material are not deep enough, and an effective surface modification technical scheme is not proposed.

[0009] Currently, there are two ways to strengthen the friction interface of the 3D printed titanium alloy artificial joint: 1) a set of cobalt-chromium-molybdenum alloy material friction components are separately printed and assembled with the artificial joint body. This method uses cobalt-chromium-molybdenum, a traditional implant material, to improve the biological and tribological performance of the friction interface and prolong the service life of the joint. However, this method has the disadvantages of long production and design cycle and high cost of the artificial joint. More importantly, the method of separate printing and assembly also causes multiple heterogeneous metal contact interfaces in the artificial joint, which causes problems such as galvanic corrosion and fretting friction during the use of the artificial joint, which not only cannot fully play the advantages of 3D printing in the design and processing of personalized artificial joints, but also may cause other potential hazards. 2) High-strength wear-resistant coating materials are prepared on the surface of the titanium alloy to improve the service life of the artificial joint. This method uses surface engineering technology to prepare protective coating materials with high wear resistance and high hardness on the surface of the artificial joint. Physical vapor deposition method is usually used for preparation, but the selection of the material system and the preparation process accuracy requirement is usually high, and the composition-structure of the coating needs to be accurately controlled to realize the preparation of high-performance coating.

[0010] In summary, it is necessary to propose new specific and feasible methods and strategies to alleviate the deficiencies of the prior art. SUMMARY

[0011] The purpose of the present application is to provide a method for preparing a titanium-carbon nanometer multilayer composite coating with interface fusion characteristics, which partially solves or alleviates the above-mentioned deficiencies in the prior art. The present application specifically adopts the following technical solutions.

[0012] In one aspect, the present application provides a preparation method.

[0013] A method for preparing a titanium-carbon nanometer multilayer composite coating with interface fusion characteristics, comprising the following steps:

[0014] S010: preparing a titanium alloy for 3D printing as a base material, placing the base material on a device sample holder, and rotating the sample holder to the front of the anode layer linear ion beam, passing argon (Ar) into the anode layer linear ion beam and ionizing it, and pre-treating (etching) the base material to remove the surface oxide film;

[0015] S020: alternately preparing Ti-TiN layers with interface fusion characteristics by cathode arc ion plating and anode layer ion beam, setting the thickness of the prepared Ti-TiN layer to be 1.6-3.0 μm, and setting the number of Ti-TiN layers to be not less than 5 layers (i.e. at least 5 layers);

[0016] S021: setting a constant current, setting the cathode arc target material current to be 70 A, setting the argon gas flow rate to be f1, and depositing on the base material for a time t1 to prepare a Ti layer;

[0017] S022: setting a constant current, setting the cathode arc target material current to be 70 A, setting the nitrogen gas flow rate to be f2, and depositing on the Ti layer for a time t2 to prepare a TiN layer; then reducing the nitrogen gas input at a speed of f3 / min and inputting argon at a speed of f4 / min, gradually changing the two gases to make the TiN layer transition to the Ti layer, and continuing for a time t3;

[0018] S023: setting a constant current, setting the cathode arc target material current to be 70 A, setting the argon gas flow rate to be f1, and depositing for a time t4 to prepare a Ti layer; reducing the argon input at a speed of f4 / min and increasing the nitrogen input at a speed of f3 / min, gradually changing the two gases to make the Ti layer transition to the TiN layer (until a TiN layer is prepared), and continuing for a time t5;

[0019] wherein the gas flow rate f3 / min is greater than the gas flow rate f4 / min;

[0020] wherein the argon gas flow rate f1 is 200 sccm; the deposition time t1 is 20 minutes; the nitrogen gas 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;

[0021] repeating S022-S023 so that the last layer prepared is a Ti layer;

[0022] S030: Rotating the sample holder to the front of the anode layer ion beam, setting a constant current, setting the ion beam current to 0.2A; setting the C2H2 gas flow rate to 40-50sccm, depositing for 30-40 minutes to prepare an amorphous carbon (DLC) lubricating layer.

[0023] The amorphous carbon material has high hardness, high biological safety and excellent wear resistance, and is an excellent lubricating coating material. However, due to its high hardness, the mechanical properties of the amorphous carbon material and the metal substrate are too different, which easily causes peeling and splitting due to mismatch of mechanical properties. Therefore, one of the focuses of the method of the present application is to design a binder layer material for the top amorphous carbon lubricating layer, which has good support and toughness. The binder layer material has moderate hardness, and plays a good supporting role between the bottom metal substrate layer and the top amorphous carbon layer, and can also absorb instantaneous impact energy, thereby improving the comprehensive performance of the entire composite material.

[0024] Further, when the substrate material is pretreated, a constant current is set, the argon gas flow rate is set to 40-50sccm; the device cavity temperature is set to not less than 200℃, the cavity gas pressure is kept constant at 2.0mTorr by adjusting the gas flow; the deposition time is 20-30 minutes.

[0025] As a preferred, the device cavity temperature is set to 200℃.

[0026] Further, in the S021, the device cavity temperature is set to not less than 200℃, and the cavity gas pressure is set to 40-50mTorr.

[0027] As a preferred, the device cavity temperature is set to 200-230℃; the cavity gas pressure is set to 45mTorr.

[0028] Further, in the S022, the device cavity temperature is set to not less than 200℃, and the cavity gas pressure is set to 40-50mTorr; the time t2 is 5 minutes.

[0029] As a preferred, the device cavity temperature is set to 200-230℃; the cavity gas pressure is set to 45mTorr.

[0030] Further, in the S022, the speed f3 / min of reducing the nitrogen gas input is set to 90sccm / minute, the speed f4 / min of inputting argon gas is set to 40sccm / minute, and the time t3 is 5 minutes.

[0031] Further, the time t4 is 10 minutes; the time t5 is 10 minutes.

[0032] As a preferred, the thickness of the prepared Ti-TiN layer is set to 1.6 μm, and the number of layers of the Ti-TiN layer is set to 5 layers (Ti: TiN = 5:5).

[0033] As a preferred, when the substrate material is pretreated, a constant current of 0.2 A is set, and the argon gas flow rate is set to 48-50 sccm; the deposition time is 30 minutes.

[0034] As a preferred, 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.

[0035] Another aspect of the present application provides a product prepared by the above preparation method.

[0036] The titanium-carbon nanometer multilayer composite coating with interface fusion characteristics prepared by the above preparation method, from bottom to top, is composed of a substrate material, an intermediate energy absorption layer, and a top amorphous carbon lubricating layer; the intermediate energy absorption layer is a Ti-TiN layer with interface fusion characteristics. Alternatively, the titanium-carbon nanometer multilayer composite coating is provided with Ti-TiN layers with interface fusion characteristics and alternating deposition as the intermediate energy absorption layer.

[0037] As a preferred, the thickness of the intermediate energy absorption layer is 1.6-3.0 μm, and the number of layers is not less than 5 layers.

[0038] Further, the substrate material and the intermediate energy absorption layer are combined by a Ti layer; the top amorphous carbon lubricating layer and the intermediate energy absorption layer are combined by a Ti layer. That is, the intermediate energy absorption layer is a structure with interface fusion characteristics of -Ti-TiN-Ti-TiN-Ti-.

[0039] Further, the overall thickness of the titanium-carbon nanometer multilayer composite coating with interface fusion characteristics is 3-3.5 μm.

[0040] The present application can also provide the application of the above preparation method and the above product.

[0041] The application of the above preparation method in the preparation of artificial wear-resistant joints.

[0042] The application of the above titanium-carbon nanometer multilayer composite coating in the preparation of artificial wear-resistant joints.

[0043] Beneficial technical effects:

[0044] Premature peeling failure of artificial joint surface protective coating materials in the service process of friction-corrosion coupling in the human body is unacceptable, and the peeling failure of the coating is caused by the high internal stress of the coating and the insufficient bonding force with the substrate. Therefore, based on the above situation, the application proposes a composite structure idea of strengthening the substrate surface bonding layer, the intermediate energy absorption layer of the bonding interface fusion structure and the top lubricating layer, and based on an alternating gradient arc ion plating technology, a titanium-carbon composite protective coating material with multi-layer interface fusion characteristics is successfully prepared, and the specific technical scheme is as follows.

[0045] Firstly, the arc ion plating technology with high ionization rate and high ion energy is used to prepare a Ti layer which can realize metallurgical bonding as a bonding layer on the surface of the artificial joint prosthesis to improve the bonding performance of the whole coating, and then a TiN-Ti layer with interface fusion characteristics is periodically deposited on the surface as an energy absorption layer to reduce the internal stress of the whole coating, and effectively slow down the stress cracking phenomenon generated in the friction impact process, thereby avoiding the brittle fracture and peeling phenomenon of the whole coating under impact. The reasons for choosing the interface fusion TiN-Ti layer are as follows: the Ti layer is soft, and the mechanical properties of the substrate material are equivalent, while the TiN layer has extremely high hardness and belongs to hard ceramic layer. By gradually changing the input of reaction gas Ar-N2 during the deposition process, the TiN-Ti layer with interface fusion characteristics can be realized. This structure does not have obvious interlayer interface structure, but has the characteristics of soft (Ti layer)-hard (TiN) alternating structure, which can effectively absorb and release the stress transmitted by the joint surface when the joint surface is subjected to instantaneous impact (such as human jumping and running), and avoid the formation of penetrating cracks in the whole coating and failure. Finally, a smooth and dense amorphous carbon layer is prepared as a top lubricating layer on the top of the multi-layer structure by using anode ion beam deposition technology. The application particularly proposes to prepare a plurality of Ti-TiN layers with interface fusion characteristics and alternating deposition by changing the deposition time on the basis of setting a specific thickness range, and the best multi-layer structure material with the best comprehensive effect is selected by experiment.

[0046] Compared with other wear-resistant coating preparation technologies, the composite structure coating material has a large design range, high process controllability, and the prepared coating material can be used as the final state of the product, instead of other additional processing (such as polishing) treatment process. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. In all the drawings, similar elements or parts are generally identified by similar reference signs. In the drawings, the elements or parts are not necessarily drawn according to the actual proportions. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0048] Figure 1 The schematic diagram of the vacuum coating device used in the present application (the left side is a cathode arc target material, Ti and TiN layers are prepared by controlling the type of gas introduced, and the right side is an anode layer ion source introducing acetylene to prepare a top layer of amorphous carbon layer);

[0049] Figure 2 The schematic diagram of the titanium-carbon multilayer coating structure prepared in Embodiment 1 of the present application (the middle layer Ti:TiN=5:5);

[0050] Figure 3 The schematic diagram of the titanium-carbon multilayer coating structure prepared in Embodiment 2 of the present application (the middle layer Ti:TiN=3:3);

[0051] Figure 4 The schematic diagram of the titanium-carbon multilayer coating structure prepared in Embodiment 3 of the present application (the middle layer Ti:TiN=1:1);

[0052] Figure 5 The schematic diagram of the Ti-TiN multilayer coating structure without a top layer of amorphous carbon prepared in Embodiment 4 of the present application (Ti:TiN=4:4);

[0053] Figure 6 The cross-sectional structure morphology diagram and EDS line scanning results of the Ti / TiN / amorphous carbon multilayer coating prepared in Embodiment 2 of the present application with interface fusion characteristics;

[0054] Figure 7 The cross-sectional structure morphology diagram and EDS line scanning results of the Ti / TiN / amorphous carbon multilayer coating prepared in Embodiment 3 of the present application with interface fusion characteristics;

[0055] Figure 8 The cross-sectional and surface structure morphology diagram of the Ti / TiN multilayer coating prepared in Embodiment 4 of the present application;

[0056] Figure 9 The tribological curve and wear rate results when the coating samples and 3D printed titanium alloy substrates prepared in different embodiments of the present application are respectively matched with polytetrafluoroethylene material;

[0057] Figure 10Bond strength testing of the titanium-carbon multilayer coating prepared for Example 1 of the present invention. DETAILED DESCRIPTION

[0058] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will be combined with the drawings in the embodiments of the present invention to make a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0059] As used herein, "and / or" includes any and all combinations of one or more of the associated items.

[0060] As used herein, "a plurality" means two or more, i.e., it includes two, three, four, five, etc.

[0061] As used in the present specification, the term "about" typically means + / - 5% of the value stated, 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, even more typically + / - 0.5% of the stated value.

[0062] In the present specification, certain embodiments can be disclosed in one format in terms of a range. It should be understood that such "in terms of a range" description is merely for the convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of the range should be considered to have specifically disclosed all possible sub-ranges and individual numerical values within the range. For example, the description of the range 1-6 should be considered to have specifically disclosed sub-ranges 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 the range, such as 1, 2, 3, 4, 5 and 6. The above rule applies regardless of the breadth of the range.

[0063] The "interface fusion feature" described in the present invention refers to 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 change feature.

[0064] The titanium-carbon composite layer prepared in the present invention has the following features.

[0065] Good hardness: the intermediate layer Ti / TN coating has very high hardness, usually between 2000-3000 HV, which is higher than the hardness of many metallic and non-metallic materials, and by adjusting the proportion and interface structure of the two, a good combination of hardness and toughness can be achieved.

[0066] Good wear resistance: Due to its high hardness, titanium nitride coating has excellent wear resistance, which can significantly prolong the service life of the substrate.

[0067] Good corrosion resistance: Titanium nitride coating shows excellent corrosion resistance in many corrosive media, which helps to protect the substrate from corrosion.

[0068] Amorphous carbon coating: Amorphous carbon is a kind of solid lubricating coating material with high hardness (the hardness of amorphous carbon coating prepared by PVD technology can be up to more than 40 GPa), good chemical stability (no chemical corrosion phenomenon in any solution) and self-lubricating property, which has important application in aerospace field. In Example 4 of the present application, the friction coefficient of the sample without top amorphous carbon coating is about 0.4, which is significantly higher than the friction coefficient of about 0.1-0.2 of the sample with amorphous carbon coating (Examples 1-3), which proves that the amorphous carbon coating has self-lubricating property.

[0069] Example 1

[0070] The present embodiment provides a multi-layer structure of titanium-carbon composite coating material, which is prepared by using a vacuum coating equipment as shown in Figure 1 The coating structure prepared in the present embodiment is shown in Figure 2 The specific preparation process is as follows.

[0071] 1. Preparation of substrate material

[0072] The 3D printed titanium alloy is used as the substrate material, and the substrate is polished before coating. The size of the substrate material is 17mm x 17mm x 3mm. Before depositing the coating, the polished 3D printed titanium alloy substrate is first placed in anhydrous ethanol and acetone for ultrasonic cleaning for 15 minutes to remove oil stains and other impurities on the surface; then the surface residual liquid is dried with a hair dryer and reserved.

[0073] 2. Pretreatment of substrate material

[0074] Sample clamping. The 3D printed titanium alloy substrate after the above pretreatment is placed on the sample holder, and the sample is fixed firmly on the sample holder and can be well electrically connected with the sample holder by using a special clamp. After placing the sample holder in the coating chamber of the equipment, the chamber is vacuumed by using a mechanical pump and a molecular pump in sequence, and the gas pressure in the chamber is controlled to be lower than 2.0 x 10 -5 Torr, and the pretreatment of the sample before coating (i.e. sample etching pretreatment) is carried out.

[0075] Sample etching pretreatment. After the vacuum degree of the vacuum chamber reaches the set value, the chamber is heated to 200℃, and the etching treatment is started after the temperature reaches the set value. Argon gas is introduced into the anode layer linear ion beam and ionized, and the ionized Ar +The ion beam etches and cleans the surface of the substrate material to remove the oxide film formed on the surface of the sample in the air, so as to increase the bonding strength between the subsequent coating material and the substrate material. The specific processing process is as follows:

[0076] Ion beam setting current: 0.2 A;

[0077] Ar gas flow rate: 48-50 sccm, keep the cavity gas pressure constant at 2.0 mTorr by adjusting the gas flow, output power 120 W;

[0078] Substrate negative bias: -100 V;

[0079] Etching time: 30 min.

[0080] 3. Preparation of intermediate energy absorption layer (coating)

[0081] Ti layer (bonding layer): set the cathode arc target material current to 70 A, argon gas flow rate 200 sccm (f1), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C. The deposition time is 20 minutes (t1).

[0082] TiN layer: set the cathode arc target material current to 70 A, nitrogen flow rate 450 sccm (f2), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C. First deposit a pure TiN layer for 5 minutes (t2), then gradually reduce the nitrogen flow rate to 90 sccm / minute (f3) for 5 minutes (t3), and gradually increase the argon flow rate to 40 sccm / minute (f4), so as to realize the interface fusion preparation of TiN-Ti layer under the premise of ensuring stable discharge of the target material. The total duration is 10 minutes.

[0083] Ti layer: set the cathode arc target material current to 70 A, argon gas flow rate 200 sccm (f1), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C, deposition time 10 minutes (t4). Then gradually reduce the argon flow rate to 40 sccm / minute (f4), and gradually increase the nitrogen flow rate to 90 sccm / minute (f3), so as to realize the preparation from pure Ti layer to pure TiN layer. The duration is 10 minutes (t5).

[0084] Repeat the above steps.

[0085] Top amorphous carbon layer: The sample holder was rotated to the front of the anode layer ion beam, the ion beam current was set to 0.2 A, the C2H2 gas flow rate was 48-50 sccm, the chamber pressure was kept constant at 2.0 mTorr by adjusting the gas flow, the output power was 120 W, the substrate negative bias was -100 V, and the deposition time was 30 minutes.

[0086] Through the above preparation process, a composite coating structure with a Ti bonding layer, a 5-cycle interface fusion structure Ti-TiN intermediate layer, and a top amorphous carbon lubricating layer is finally achieved.

[0087] In this embodiment, the Ti bonding layer has a thickness of 0.6 μm (multiplied by 2), the intermediate alternating TiN-Ti layer has a thickness of 1.6 μm, the top layer has a thickness of 0.5 μm, and the total thickness is about 3.3 μm.

[0088] Example 2

[0089] This embodiment provides another example of a titanium-carbon composite coating material.

[0090] The substrate material preparation and pretreatment involved in the preparation process of this embodiment are the same as those of Example 2, except that the number of layers of the intermediate layer and the deposition time are different. The prepared coating structure is as shown in Figure 3 .

[0091] The intermediate energy absorption layer (coating) is prepared as follows:

[0092] Ti layer (bonding layer): The cathode arc target material current is set to 70 A, the argon gas flow rate is 200 sccm (f1), the chamber pressure is controlled at 45 mTorr, the substrate negative bias is -60 V, and the chamber temperature is 200-230°C. The deposition time is 20 minutes (t1).

[0093] TiN layer: The cathode arc target material current is set to 70 A, the nitrogen gas flow rate is 450 sccm (f2), the chamber pressure is controlled at 45 mTorr, the substrate negative bias is -60 V, and the chamber temperature is 200-230°C. A pure TiN layer is first deposited for 10 minutes (t2), and then for the next 10 minutes (t3), the nitrogen gas is reduced at a rate of 45 sccm / minute (f3), and the argon gas is introduced at a rate of 20 sccm / minute (f4). Through gradual change of the two gases, the interface fusion of the TiN-Ti layer is realized under the premise of ensuring stable discharge of the target material. The total duration is 20 minutes.

[0094] Ti layer: set the cathode arc target material current to 70 A, argon flow rate 200 sccm (f1), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C, deposition time 10 minutes (t4). Then reduce the argon flow rate to 20 sccm / min (f4) within 10 minutes (t5), gradually introduce nitrogen at a rate of 45 sccm / min (f3), and gradually time from the preparation of the pure Ti layer to the pure TiN layer.

[0095] Ti-TiN as a deposition cycle, a total of 3 cycles, as shown in Figure 3 the structure of the structure of the intermediate layer with 3 cycles.

[0096] Top amorphous carbon layer: rotate the sample holder to the front of the anode layer ion beam, set the ion beam current to 0.2 A, C2H2 flow rate: 48-50 sccm, keep the cavity pressure constant at 2.0 mTorr by adjusting the gas flow, output power 120 W, substrate negative bias: -100 V, deposition time 30 minutes.

[0097] In this embodiment, the Ti bonding layer thickness is 0.6 μm (times 2), the intermediate alternating TiN-Ti layer thickness is 1.6 μm, the top layer thickness is 0.5 μm, and the total thickness is about 3.3 μm.

[0098] Example 3

[0099] This embodiment is based on Example 3, and proposes another improved example of preparation of titanium nitride coating material.

[0100] The substrate material preparation and pretreatment involved in the preparation process of this embodiment are the same as those of Example 3, the difference is that the number of layers and deposition time of the intermediate layer are different, and the prepared coating structure is as shown in Figure 4 .

[0101] Optimized process parameters:

[0102] Ti layer (bonding layer): set the cathode arc target material current to 70 A, argon flow rate 200 sccm (f1), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C. Deposition time 20 minutes (t1).

[0103] TiN layer: Set cathode arc target material current 70 A, nitrogen flow 450 sccm (f2), control cavity pressure 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230 °C, deposit 20 minutes (t2) pure TiN layer. Subsequently, within 10 minutes (t3) to reduce the nitrogen inlet speed of 45 sccm / min (f3), the speed of 20 sccm / min (f4) of argon, by gradually changing the two kinds of gas, to ensure the target stable discharge before the interface fusion of TiN-Ti layer preparation. The total duration is 30 minutes.

[0104] Ti layer: Set cathode arc target material current 70 A, argon flow 200 sccm (f1), control cavity pressure 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230 °C, deposition time, 10 minutes (t4). Subsequently, reduce the argon speed of 20 sccm / min (f4), gradually increase the nitrogen speed of 45 sccm / min (f3), gradually from the preparation of pure Ti layer to pure TiN layer, for 10 minutes (t5).

[0105] Top amorphous carbon layer: ion beam current 0.2 A, C2H2 flow rate: 48-50 sccm, by adjusting the gas flow to maintain the cavity pressure constant at 2.0 mTorr, output power 120 W, substrate negative bias: -100 V, deposition time 30 minutes.

[0106] It can be understood that Ti-TiN is a deposition cycle, and n cycles can be deposited according to needs to prepare a titanium nitride coating material.

[0107] Example 4

[0108] This embodiment provides an example of the operation of the equipment of the titanium nitride coating without a top amorphous carbon layer.

[0109] This embodiment is based on Example 1, and another example of preparing a titanium nitride coating material without a top amorphous carbon coating is provided, the difference being that the number of layers and deposition time of the intermediate layer are different, and the prepared coating structure is as shown in Figure 5 .

[0110] Ti layer: Set cathode arc target material current 70 A, argon flow 200 sccm (f1), control cavity pressure 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230 °C, deposition time 15 minutes (t1).

[0111] TiN layer: Set the cathode arc target material current to 70 A, nitrogen flow rate 450 sccm (f2), control the cavity pressure to 45 mTorr, substrate negative bias -60 V, cavity temperature 200-230°C, deposition time 13 minutes (t2).

[0112] The above Ti-TiN layer is one cycle, and a total of 4 cycles are deposited.

[0113] Top layer TiN layer: The process parameters are the same as those for preparing the second layer TiN, and the deposition time is extended to 30 minutes to increase the thickness. Finally, a nitrogen-based composite coating material with a Ti-TiN alternating structure is formed.

[0114] Example 5

[0115] This example provides performance testing of the plurality of coating materials prepared above.

[0116] 1. Coefficient of friction

[0117] The coating materials prepared in Examples 1-4, as well as the 3D printed titanium alloy substrate material used as a control test group, were subjected to friction and wear performance testing. The results of the coating friction coefficient and wear rate obtained by testing are shown in Table 1 and Figure 9 .

[0118] Table 1 Coefficient of friction

[0119]

[0120] As can be seen from the results in Table 1, the friction coefficient and wear rate of the samples prepared with the composite coating (Examples 1-4) are significantly lower than those of the substrate titanium alloy material, indicating that the coating can indeed significantly reduce the wear of the substrate material. Further, from the friction coefficient curve Figure 9 it can be seen that after the top layer of amorphous carbon is prepared, the friction coefficient of the coating is lower than that of the sample with a TiN coating on the top layer, and the surface top layer prepared with lubricating amorphous carbon can further reduce wear. Further, from the friction coefficient curve, it can be seen that the titanium-carbon composite coating with a Ti:TiN ratio of 5:5 in the middle layer has the lowest friction coefficient, and the curve is smooth and flat throughout the friction process, with minimal fluctuations. The friction coefficients of the titanium-carbon composite coatings with other middle layer ratios show a gradual increase and significant fluctuations, which indicates that the middle layer of the coating cannot continuously provide good stress absorption during the surface friction process, resulting in the local collapse of the coating, which will accelerate the failure of the coating. This shows that the multi-layer "interface fusion feature" 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, significantly reducing the wear of the substrate material.

[0121] From the index of the coating tribological performance, the sample with the multi-layer structure titanium-carbon composite coating (the proportion of Ti:TiN in the intermediate layer is 5:5) can significantly reduce the substrate wear, and can inhibit the coating peeling during long time wear, thereby prolonging the service life of the coating.

[0122] 2. Coating structure characterization test

[0123] Figure 6 The cross-sectional structure morphology and EDS line scanning results of the Ti / TiN / amorphous carbon multi-layer coating with interface fusion characteristics prepared in Example 1 of the present application are shown in the figure. As can be seen from the figure, there is no obvious interface structure between the dark part (TiN layer) and the light part (Ti layer), and the contrast difference between them has a gradual change feature, indicating that the interface structure has a fusion feature. The total thickness of the coating is about 3.3 μm, and the coating has no interlayer cracking defect.

[0124] Figure 7 The cross-sectional structure morphology and EDS line scanning results of the Ti / TiN / amorphous carbon multi-layer coating with interface fusion characteristics prepared in Example 3 of the present application are shown in the figure. As can be seen from the cross-sectional SEM results of the coating, the total thickness of the coating is about 3.4 μm, the interface surface of the coating is complete, the EDS element surface distribution results show that the composition transition characteristics between Ti-TiN layers are obvious, and the contrast difference between them has a gradual change feature, indicating that the interface structure has a fusion feature.

[0125] Figure 8 The cross-sectional SEM results of the multi-layer titanium nitride coating without amorphous carbon top layer prepared in Example 4 of the present application are shown in the figure. The figure shows that the coating is composed of multi-layer structure, the total thickness of the coating is about 1.82 μm, the thickness of the Ti layer is 280 nm, and the thickness of the intermediate TiN layer is 300 nm. The interface surface of the coating is complete, and there is no interlayer cracking phenomenon, but the overall surface of the coating is relatively rough, and there are many large particle defects, which is one of the shortcomings of the ordinary arc ion plating technology for preparing the coating; and the composition transition characteristics between Ti-TiN layers are not obvious, indicating that the interface structure does not have a fusion feature.

[0126] 3. Coating mechanical property test

[0127] The mechanical properties of the coating were tested by nanoindentation test technology, and the test results are shown in Table 2. It is found by comparison that the hardness of the coating of Examples 1-4 all exceeds 13 GPa, which is significantly higher than 3.5 GPa of the 3D printed titanium alloy base material. It shows that the coating can significantly improve the hardness of the base titanium alloy. In addition, the hardness of the samples with top amorphous carbon coating (Examples 1-3) is higher than that of the sample without top amorphous carbon in Example 4, and the more the number of cycles with the interface fusion characteristics in the multilayer structure, although the overall hardness of the sample decreases to a certain extent, the elastic modulus rises, and the toughness of the surface coating is improved, which will be beneficial to avoid brittle fracture of the coating and improve the overall service life of the coating.

[0128] Table 2 Mechanical property test results of the coating and the base material

[0129]

[0130] 4. Coating and base material bonding performance test

[0131] Figure 10 The bonding strength test of the titanium-carbon multilayer coating prepared in Example 1 of the present application (intermediate layer Ti: TiN = 5:5) shows that the bonding force of the multilayer titanium-carbon composite coating prepared by the alternating gradual change arc ion plating technology reaches 32 N, which has good bonding performance; the bonding strength of general amorphous carbon coating is about 20 N.

[0132] It should be noted that in this document, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0133] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative, not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection of the present application.

Claims

1. A method for preparing a titanium-carbon nano-multilayer composite coating with interfacial fusion characteristics, characterized in that, The method comprises the following steps: S010: preparing a 3D-printed titanium alloy as a base material, placing the base material on a device sample holder, rotating the sample holder to the front of an anode layer linear ion beam, introducing argon into the anode layer linear ion beam and ionizing it, and pre-treating the base material to remove the surface oxide film; S020: alternately preparing a Ti-TiN layer with interface fusion characteristics by using cathode arc ion plating and anode layer ion beam, setting the thickness of the prepared Ti-TiN layer to be 1.6-3.0 μm, and the number of Ti-TiN layers to be not less than 5 layers; S021: setting a constant current, setting the cathode arc target material current to be 70 A, setting the argon flow rate to be f1, and depositing on the base material for a time t1 to prepare a Ti layer; S022: setting a constant current, setting the cathode arc target material current to be 70 A; setting the nitrogen flow rate to be f2, depositing on the Ti layer for a time t2 to prepare a TiN layer, then reducing the nitrogen flow rate at a speed of f3 / min and increasing the argon flow rate at a speed of f4 / min, gradually changing the two gases to make the TiN layer transition to the Ti layer, and continuing for a time t3; S023: setting a constant current, setting the cathode arc target material current to be 70 A, setting the argon flow rate to be f1, and depositing for a time t4 to prepare a Ti layer; reducing the argon flow rate at a speed of f4 / min and increasing the nitrogen flow rate at a speed of f3 / min, gradually changing the two gases to make the Ti layer transition to the TiN layer, and continuing for a time t5; wherein the gas flow rate f3 / min is greater than the gas flow rate f4 / min; wherein 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; repeating S022-S023 to make the last prepared layer a Ti layer; S030: rotating the sample holder to the front of the anode layer ion beam, setting a constant current, setting the ion beam current to be 0.2 A, setting the C2H2 gas flow rate to be 40-50 sccm, and depositing for 30-40 minutes to prepare an amorphous carbon lubricating layer.

2. The production method according to claim 1, wherein When pre-treating the base material, set a constant current, set the argon flow rate to be 40-50 sccm, set the device cavity temperature to be not less than 200℃, keep the cavity gas pressure constant at 2.0 mTorr by adjusting the gas flow, and etch for 20-30 minutes.

3. The production method according to claim 1, wherein In S021, set the device cavity temperature to be not less than 200℃, and set the cavity gas pressure to be 40-50 mTorr.

4. The production method according to claim 1, wherein In S022, set the device cavity temperature to be not less than 200℃, set the cavity gas pressure to be 40-50 mTorr, and the time t2 is 5 minutes.

5. The production method according to claim 1, wherein The S022 sets the speed f3 / min of the nitrogen gas flow to 90 sccm / min, sets the speed f4 / min of the argon gas flow to 40 sccm / min, and sets the time t3 to 5 minutes.

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

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

8. The production method according to claim 2, wherein The constant current is set to 0.2 A, and the argon gas flow is set to 48-50 sccm when the substrate material is pretreated; the etching time is 30 minutes.

9. The production method according to claim 1, characterized by, The S030 sets the C2H2 gas flow to 48-50 sccm, and the cavity pressure is kept constant at 2.0 mTorr by adjusting the gas flow.

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