Composite coating and method for its production, implant material and medical device

Abstract

The present application relates to the technical field of coating preparation, and discloses a composite coating, a preparation method thereof, an implant material and a medical device. The disclosed composite coating comprises a Ti transition layer, a first ceramic layer and a second ceramic layer arranged on the surface of a substrate in sequence, the main component of the first ceramic layer is Ti3SiC2, and the main component of the second ceramic layer is Ti3(Si, Ag)C2. The disclosed preparation method comprises sequentially depositing a Ti transition layer, a first ceramic layer with the main component of Ti3SiC2 and a second ceramic layer with the main component of Ti3(Si, Ag)C2 on the surface of a substrate. The disclosed implant material comprises the above composite coating deposited on the surface of a substrate. The disclosed medical device comprises the above implant material. The composite coating of the present application can enhance the wear resistance and corrosion resistance of titanium alloy, and has the ability to resist bacterial infection in the early stage of implantation.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology, and more specifically, to composite coatings and their preparation methods, implantable materials, and medical devices. Background Technology

[0002] Titanium alloys, due to their good biocompatibility, low elastic modulus, and excellent corrosion resistance, have wide applications in implantable medical devices, including dental implants, materials for some orthodontic surgeries, restorative materials for hip, knee, shoulder, spine, elbow, and wrist bones, as well as fixation components such as bone screws, nuts, and plates. However, as implantable medical device materials, the ion dissolution of titanium alloys in body fluid environments directly affects cell adhesion and proliferation in the early stages of implantation, increasing the osseointegration period, and corrosion resistance needs improvement. Furthermore, the wear particles generated after friction and wear of titanium alloys can easily induce inflammation, requiring improved wear resistance. In addition, titanium alloy surfaces lack antibacterial properties, making them susceptible to infection by bacteria and other pathogenic microorganisms, which can easily lead to implant device failure. To address these issues, surface modification is necessary. However, a single coating is insufficient to achieve composite functionalization of the titanium alloy surface, and the combination of multiple heterogeneous coatings introduces high residual stress, easily causing film cracking, peeling, and failure, resulting in decreased film-substrate adhesion. Therefore, how to enhance the film-substrate bonding force between the substrate and the coating through composite surface modification, and improve its wear resistance, corrosion resistance and antibacterial properties in the implantation environment, is an important issue to promote the application of titanium alloy materials in implantable devices.

[0003] Ti3SiC2 is a ternary layered compound in the MAX phase. Due to its unique crystal structure, it combines the excellent properties of both metals and ceramics. It possesses the high melting point, high hardness, wear resistance, and oxidation resistance of ceramics, while also exhibiting the low coefficient of friction and self-lubricating properties of metals. It has good machinability and excellent overall performance, thus showing broad application prospects in multiple fields. Specifically, Ti3SiC2 has a low coefficient of friction and excellent self-lubricating properties comparable to graphite; its corrosion resistance is superior to that of metals; and its elemental composition, Ti-Si-C, does not introduce elements harmful to the human body compared to titanium alloys, making it a promising candidate for wear-resistant and corrosion-resistant coatings on titanium alloy surfaces. However, the biggest obstacle to the development of Ti3SiC2 as a coating is the stringent preparation methods. While chemical vapor deposition or magnetron sputtering methods have been reported to prepare Ti3SiC2 coatings, these methods require high synthesis temperatures, typically 800–1300℃, resulting in prohibitively high costs.

[0004] To improve antibacterial properties, a conventional method is to implant Ag ions into the material surface, aiming to achieve antibacterial effects through the slow release of Ag ions. However, ion implantation equipment is complex and expensive, with relatively low production efficiency, resulting in very high process costs. To obtain a coating with excellent overall antibacterial and wear-resistant properties, other coating operations are required on the material before implantation, further increasing the process difficulty and overall cost. Therefore, to achieve excellent overall antibacterial, wear-resistant, and corrosion-resistant properties on titanium alloy surfaces while controlling process complexity, optimized design and preparation of composite coatings are necessary.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide composite coatings and their preparation methods, implant materials, and medical devices.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides a composite coating suitable for implant materials, comprising:

[0009] A Ti transition layer, a first ceramic layer, and a second ceramic layer are sequentially disposed on the surface of the substrate. The main component of the first ceramic layer is Ti3SiC2, and the main component of the second ceramic layer is Ti3(Si,Ag)C2.

[0010] In an optional embodiment, the thickness of the Ti transition layer is 0.3–1 μm, the thickness of the first ceramic layer is 5–10 μm, and the thickness of the second ceramic layer is 0.5–1 μm.

[0011] Secondly, the present invention provides a method for preparing a composite coating, comprising:

[0012] A Ti transition layer, a first ceramic layer with Ti3SiC2 as the main component, and a second ceramic layer with Ti3(Si,Ag)C2 as the main component are sequentially deposited on the substrate surface.

[0013] In an optional implementation, a Ti transition layer, a first ceramic layer, and a second ceramic layer are deposited using a high-power pulsed magnetron sputtering method. The target material used for depositing the Ti transition layer is a Ti target, the target material used for depositing the first ceramic layer is a Ti3SiC2 target, and the target material used for depositing the second ceramic layer is a Ti-Si-C-Ag target.

[0014] In an optional implementation, when high-power pulsed magnetron sputtering is used to deposit a Ti transition layer, and / or a first ceramic layer with Ti3SiC2 as the main component, and / or a second ceramic layer with Ti3(Si,Ag)C2 as the main component, the operating parameters are:

[0015] The working pulse voltage is 100–400V, the pulse width is 30–300μs, the frequency is 400–600Hz, the base bias voltage is -30–-100V, and the working pressure of argon gas is 0.2–0.9Pa.

[0016] The substrate is heated to 200–300°C before deposition.

[0017] In an optional embodiment, before depositing the Ti transition layer, the substrate is further cleaned using a hollow cathode plasma source. During cleaning, the working pressure of high-purity argon gas is 0.5 to 1.5 Pa, the discharge current of the hollow cathode is 30 to 60 A, and the substrate bias voltage is -200 to -600 V.

[0018] In an optional embodiment, before depositing the Ti transition layer, the first ceramic layer and / or the second ceramic layer, a movable baffle is used to block the substrate for target sputtering self-cleaning.

[0019] In an optional embodiment, when depositing the second ceramic layer, the Ti-Si-C-Ag target material is prepared by hot pressing sintering or hot isostatic pressing sintering, and the molar ratio of the main components in the target material is Ti:Si:C:Ag = 6:1.0~1.2:1.0~1.2:3.6~4.1.

[0020] Thirdly, the present invention provides an implant material comprising a substrate and a composite coating deposited on the surface of the substrate as described in the foregoing embodiments, or comprising a substrate and a composite coating deposited on the surface of the substrate using any of the preparation methods described in the foregoing embodiments.

[0021] Fourthly, the present invention provides a medical device comprising an implantable material as described in the foregoing embodiments.

[0022] The present invention has the following beneficial effects:

[0023] This invention achieves low-temperature deposition of Ti3SiC2 and innovatively prepares Ti3(Si,Ag)C2, realizing solid solution of Ag in Ti3SiC2 and occupying Si sites. The Ti-Ag bond is weak and easily broken under corrosion and other conditions, allowing Ag ions to dissolve. The composite coating obtained through the above design, suitable for implant materials, not only improves the antibacterial properties of titanium alloys in the early stages of implantation, preventing bacterial infection, but also enhances the wear resistance and corrosion resistance of the implant material during service. It can enhance the performance of titanium alloy implant materials to meet specific functional requirements at different stages, exhibiting excellent overall performance. Furthermore, because a Ti transition layer is deposited before the Ti3SiC2 layer, the composite coating has strong adhesion to the substrate. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a diagram showing the interface morphology of the composite coating obtained in Example 1 of the present invention.

[0026] Figure 2 This is a microscopic morphology image of the composite coating surface obtained in Example 1 of the present invention;

[0027] Figure 3 This is a TEM image of the Ti3SiC2 layer in the composite coating obtained in Example 2 of the present invention;

[0028] Figure 4 The survival rate of Escherichia coli on the surface of the composite coating obtained in Example 2 of this invention (right) is compared with that of the control sample (left). Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] The following is a detailed description of the composite coating, its preparation method, plant materials, and medical devices provided in the embodiments of the present invention.

[0031] An embodiment of the present invention provides a composite coating suitable for implant materials, comprising:

[0032] A Ti transition layer, a first ceramic layer, and a second ceramic layer are sequentially disposed on the surface of the substrate. The main component of the first ceramic layer is Ti3SiC2, and the main component of the second ceramic layer is Ti3(Si,Ag)C2.

[0033] The ceramic layer whose main component is Ti3SiC2 refers to the fact that it is mainly composed of Ti3SiC2 phase, but there are still unavoidable small amounts of TiC and Ti5Si3 phase.

[0034] The ceramic layer whose main component is Ti3(Si,Ag)C2 refers to the fact that it is mainly composed of Ti3(Si,Ag)C2 phase, but there are still unavoidable small amounts of TiC and Ti5Si3 phase.

[0035] Ti3SiC2 is a ternary layered compound MAX phase. Due to its unique crystal structure, it combines the excellent properties of both metals and ceramics, exhibiting good machinability and superior overall performance. Ti3SiC2 has a low coefficient of friction and excellent self-lubricating properties, comparable to graphite. Its corrosion resistance is superior to metals. Moreover, its elemental composition, Ti-Si-C, does not introduce elements harmful to the human body compared to titanium alloys. Therefore, as a surface coating for titanium alloys, it can effectively improve the surface hardness, wear resistance, and corrosion resistance. Furthermore, the preparation of a Ti3(Si,Ag)C2 coating, achieving Ag solid solution within Ti3SiC2, allows for the slow release of Ag during titanium alloy implantation, resulting in excellent antibacterial properties and preventing infection in the early stages of implantation. Therefore, preparing a composite coating on the surface of titanium alloy implant materials not only improves the antibacterial properties of titanium alloys in the early stages of implantation, preventing bacterial infection, but also enhances the wear resistance and corrosion resistance of the implant material during service. This enhances the specific functional requirements of titanium alloy implant materials at different stages, resulting in excellent overall performance. Depositing a Ti transition layer before depositing the Ti3SiC2 layer can improve the adhesion between the composite coating and the substrate. Moreover, the composition and structure of the second ceramic layer are similar to those of the first ceramic layer, resulting in low interfacial stress and excellent adhesion between the coatings.

[0036] Furthermore, to ensure better overall performance of the coating, the thickness of the Ti transition layer is 0.3–1 μm, the thickness of the first ceramic layer is 5–10 μm, and the thickness of the second ceramic layer is 0.5–1 μm.

[0037] The method for preparing the composite coating provided in this application includes:

[0038] A Ti transition layer, a first ceramic layer with Ti3SiC2 as the main component, and a second ceramic layer with Ti3(Si,Ag)C2 as the main component are sequentially deposited on the substrate surface;

[0039] Preferably, the thickness of the deposited Ti transition layer is 0.3–1 μm, the thickness of the deposited ceramic layer with Ti3SiC2 as the main component is 5–10 μm, and the thickness of the deposited second ceramic layer with Ti3(Si,Ag)C2 as the main component is 0.5–1 μm.

[0040] The specific preparation method is as follows:

[0041] S1. Matrix pretreatment:

[0042] The substrate sample was ground, polished, cleaned with alcohol and acetone by ultrasonic vibration, and then dried.

[0043] S2, Matrix Cleaning:

[0044] The pretreated titanium alloy was placed into a composite magnetron sputtering deposition system, and the chamber vacuum was evacuated to <8×10⁻⁶. -3 Pa, then argon gas is introduced. The working pressure of high-purity argon gas is 0.5 to 1.5 Pa (e.g., 0.5 Pa, 1 Pa, or 1.5 Pa). The discharge current of the hollow cathode is 30 to 60 A (e.g., 30 A, 40 A, 50 A, or 60 A). The substrate bias voltage is -200 to -600 V (e.g., -200 V, -400 V, or -600 V). The substrate workpiece is cleaned using a hollow cathode plasma source.

[0045] S3, Coating Deposition:

[0046] A Ti transition layer, a first ceramic layer with Ti3SiC2 as the main component, and a second ceramic layer with Ti3(Si,Ag)C2 as the main component were deposited using high-power pulsed magnetron sputtering (HIPIMS).

[0047] Specifically, the substrate is heated to 200–300°C (e.g., 200°C, 250°C, or 300°C), the high-power pulsed magnetron sputtering power supply is turned on, and the operating parameters are controlled as follows: the working pulse voltage is 100–400V (e.g., 100V, 200V, 300V, or 400V), and the pulse width is 30–300μs (e.g., 30μs, 50μs, 80μs, 100μs, 150μs, 2…). The operating frequency is 400–600 Hz (e.g., 400 Hz, 450 Hz, 500 Hz, 550 Hz, or 600 Hz), the base bias is -30 to -100 V (e.g., -30 V, -50 V, -80 V, or -100 V), and the working pressure of argon is 0.2–0.9 Pa (e.g., 0.2 Pa, 0.5 Pa, or 0.9 Pa).

[0048] A movable baffle is used to block the substrate and perform air sputtering self-cleaning on the Ti target. After cleaning, the baffle is removed and the Ti transition layer is deposited. When the thickness of the Ti transition layer is 0.3 to 1 μm, the power is turned off and the target is replaced with a Ti3SiC2 target.

[0049] The substrate temperature is still controlled at 200–300℃ (e.g., 200℃, 250℃, or 300℃). The high-power pulsed magnetron sputtering power supply is turned on, and the operating parameters are controlled as follows: operating pulse voltage 100–400V (e.g., 100V, 200V, 300V, or 400V), pulse width 30–300μs (e.g., 30μs, 50μs, 80μs, 100μs, 150μs, 2…). The operating frequency is 400–600 Hz (e.g., 400 Hz, 450 Hz, 500 Hz, 550 Hz, or 600 Hz), the base bias is -30 to -100 V (e.g., -30 V, -50 V, -80 V, or -100 V), and the working pressure of argon is 0.2–0.9 Pa (e.g., 0.2 Pa, 0.5 Pa, or 0.9 Pa).

[0050] A movable baffle was used to block the substrate and the Ti3SiC2 target was sputter-cleaned. After cleaning, the baffle was removed and a ceramic layer with Ti3SiC2 as the main component was deposited. When the thickness of the ceramic layer was 5-10 μm, the power was turned off and the target was replaced with a Ti-Si-C-Ag target.

[0051] The substrate temperature is still controlled at 200–300℃ (e.g., 200℃, 250℃, or 300℃). The high-power pulsed magnetron sputtering power supply is turned on, and the operating parameters are controlled as follows: operating pulse voltage 100–400V (e.g., 100V, 200V, 300V, or 400V), pulse width 30–300μs (e.g., 30μs, 50μs, 80μs, 100μs, 150μs, 2…). The operating frequency is 400–600 Hz (e.g., 400 Hz, 450 Hz, 500 Hz, 550 Hz, or 600 Hz), the base bias is -30 to -100 V (e.g., -30 V, -50 V, -80 V, or -100 V), and the working pressure of argon is 0.2–0.9 Pa (e.g., 0.2 Pa, 0.5 Pa, or 0.9 Pa).

[0052] A movable baffle is used to block the substrate and perform air sputtering self-cleaning on the Ti-Si-C-Ag target. After cleaning, the baffle is removed and a ceramic layer with Ti3(Si,Ag)C2 as the main component is deposited. When the thickness of the ceramic layer is 0.5 to 1 μm, the power is turned off.

[0053] In this application, setting the parameters of the high-power pulsed magnetron sputtering deposition coating within the above-mentioned range can obtain a coating with better properties such as density, hardness, strength, and corrosion resistance. In particular, when depositing Ti3SiC2 and / or Ti3(Si,Ag)C2 coatings, the bias voltage should be within the range required by this application. When the bias voltage is lower than the range required by this application, the prepared coating will be relatively loose and cracked. When it is higher than the range required by this application, the composition will be deviated due to the backsputtering effect, making it difficult to form a coating whose main components are Ti3SiC2 and / or Ti3(Si,Ag)C2.

[0054] The embodiments of this application preferably employ high-power pulsed magnetron sputtering to deposit the coating. Since the power is much higher than that of ordinary DC magnetron sputtering, the sputtered ions have very high energy. The Ti3SiC2 coating can be deposited by heating the substrate to 200-300°C. Compared with existing vapor deposition or ordinary magnetron sputtering methods, it does not require a high temperature of 800-1300°C, and its cost is low.

[0055] High-power pulsed magnetron sputtering technology is developed by combining DC magnetron sputtering technology with pulsed power technology. It has a very high peak power, can obtain high-density plasma, and the sputtered target ions have a high ionization rate, which can enable the deposited ions to obtain a high energy peak. The ions are accelerated to obtain additional energy to impact the substrate surface, making it possible to prepare complex structure coatings at low temperatures. It also has great advantages in improving the hardness, density, and adhesion of the film to the substrate. In this invention, high-power pulsed magnetron sputtering is used to deposit a second ceramic layer with the main component of Ti3SiC2 as Ti3(Si,Ag)C2 on the surface of a first ceramic layer with the main component of Ti3SiC2. Ag is dissolved in Ti3SiC2. On the one hand, the continuity of the coating composition and the uniformity of the preparation method are achieved. On the other hand, Ag is introduced into the coating more efficiently, and the distribution of Ag in the coating thickness direction is more uniform. The release uniformity of Ag during the slow release period after coating implantation is also better.

[0056] The implant material provided in the embodiments of this application includes a substrate and a composite coating deposited on the surface of the substrate, or includes a substrate and a composite coating deposited on the surface of the substrate using a preparation method.

[0057] Furthermore, the base material can be a titanium alloy.

[0058] Because of the aforementioned composite coating on its surface, the implant material exhibits superior wear resistance, corrosion resistance, and antibacterial properties.

[0059] The medical devices provided in this application include the implantable materials provided in this application.

[0060] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0061] Example 1

[0062] This application provides a method for preparing a composite coating suitable for implant materials, specifically:

[0063] S1. Matrix pretreatment:

[0064] The substrate (TC4) sample was ground, polished, cleaned with alcohol and acetone by ultrasonic vibration, and then dried.

[0065] S2, Matrix Cleaning:

[0066] The pretreated titanium alloy was placed into a composite magnetron sputtering deposition system, and the chamber vacuum was evacuated to 5 × 10⁻⁶. -3 Pa, then argon gas is introduced. The working pressure of high-purity argon gas is 1.0 Pa, the discharge current of hollow cathode is 50 A, the substrate bias voltage is -500 V, and the substrate workpiece is cleaned with hollow cathode plasma source for 10 min.

[0067] S3, Coating Deposition:

[0068] Adjust the working pressure of argon to 0.5 Pa, heat the substrate to 300 °C, turn on the high-power pulsed magnetron sputtering power supply, and control the operating parameters as follows: working pulse voltage of 100 V, pulse width of 30 μs, frequency of 400 Hz, and substrate bias voltage of -100 V.

[0069] A movable baffle was used to block the substrate and perform air sputtering self-cleaning on the Ti target. After cleaning, the baffle was removed and the Ti transition layer was deposited. The thickness of the obtained Ti transition layer was 0.3 μm.

[0070] Then, the target material was changed to Ti3SiC2, the substrate temperature was kept at 300℃, the working pressure of argon gas was kept at 0.5Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 300V, pulse width of 100μs, frequency of 600Hz, substrate bias voltage of -50V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of Ti3SiC2 target material.

[0071] After cleaning, the baffle was removed and a ceramic layer with Ti3SiC2 as the main component was deposited, resulting in a ceramic layer with a thickness of 3μm and Ti3SiC2 as the main component.

[0072] Next, the target material was changed to a Ti-Si-C-Ag target with a molar ratio of Ti:Si:C:Ag = 6:1.1:1.1:3.8 prepared by hot pressing. The substrate temperature was maintained at 300℃, the working pressure of argon gas was maintained at 0.5Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 350V, pulse width of 200μs, frequency of 500Hz, substrate bias voltage of -80V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of the Ti-Si-C-Ag target.

[0073] After cleaning, the baffle was removed and a ceramic layer with Ti3(Si,Ag)C2 as the main component was deposited, resulting in a ceramic layer with a thickness of 0.7 μm and Ti3(Si,Ag)C2 as the main component.

[0074] The interface morphology of the composite coating obtained in this embodiment was photographed, such as... Figure 1 As shown, Figure 1 From left to right, the layers are the substrate, the Ti transition layer, the Ti3SiC2 ceramic layer, and the Ti3(Si,Ag)C2 ceramic layer (too thin to have a clear contrast).

[0075] The surface microstructure of the composite coating prepared in this embodiment was photographed using a scanning electron microscope, such as... Figure 2 As shown, from Figure 2 The coating surface is smooth and uniform with a dense structure.

[0076] Example 2

[0077] This application provides a method for preparing a composite coating suitable for implant materials, specifically:

[0078] S1. Matrix pretreatment:

[0079] The substrate (TC4) sample was ground, polished, cleaned with alcohol and acetone by ultrasonic vibration, and then dried.

[0080] S2, Matrix Cleaning:

[0081] The pretreated titanium alloy was placed into a composite magnetron sputtering deposition system, and the chamber vacuum was evacuated to 5 × 10⁻⁶. -3 Pa, then argon gas is introduced. The working pressure of high-purity argon gas is 1.5 Pa, the discharge current of hollow cathode is 30 A, the substrate bias voltage is -300 V, and the substrate workpiece is cleaned with hollow cathode plasma source for 10 min.

[0082] S3, Coating Deposition:

[0083] Adjust the working pressure of argon to 0.8 Pa, heat the substrate to 200 °C, turn on the high-power pulsed magnetron sputtering power supply, and control the operating parameters as follows: working pulse voltage of 200 V, pulse width of 100 μs, frequency of 500 Hz, and substrate bias voltage of -50 V.

[0084] A movable baffle was used to block the substrate and perform air sputtering self-cleaning on the Ti target. After cleaning, the baffle was removed and the Ti transition layer was deposited, resulting in a Ti transition layer with a thickness of 0.45 μm.

[0085] Then, the target material was changed to Ti3SiC2 target material, the substrate temperature was kept at 200℃, the working pressure of argon gas was kept at 0.8Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 400V, pulse width of 300μs, frequency of 400Hz, substrate bias voltage of -50V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of Ti3SiC2 target material.

[0086] After cleaning, the baffle was removed and a ceramic layer with Ti3SiC2 as the main component was deposited, and a ceramic layer with a thickness of 5μm and Ti3SiC2 as the main component was obtained.

[0087] Next, the target material was changed to a Ti-Si-C-Ag target with a molar ratio of Ti:Si:C:Ag = 6:1.0:1.0:3.6 prepared by hot isostatic pressing. The substrate temperature was kept at 200℃, the working pressure of argon gas was kept at 0.5Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 100V, pulse width of 30μs, frequency of 400Hz, substrate bias voltage of -30V, and a movable baffle was used to block the substrate. The Ti-Si-C-Ag target was then air-sputtered for self-cleaning.

[0088] After cleaning, the baffle was removed and a ceramic layer with Ti3(Si,Ag)C2 as the main component was deposited, resulting in a ceramic layer with a thickness of 0.5 μm and Ti3(Si,Ag)C2 as the main component.

[0089] Transmission electron microscopy (TEM) was used to capture images of the first ceramic layer, whose main component is Ti3SiC2, in the composite coating prepared in this embodiment. (See image below.) Figure 3 As shown, from Figure 3 It can be seen from the image that the prepared Ti3SiC2 has different morphology and small grain size, and a clear MAX phase structure is observed in the high-resolution image. Its selected area diffraction pattern further proves that the coating grains are polycrystalline Ti3SiC2.

[0090] Example 3

[0091] This application provides a method for preparing a composite coating suitable for implant materials, specifically:

[0092] S1. Matrix pretreatment:

[0093] The substrate (TC4) sample was ground, polished, cleaned with alcohol and acetone by ultrasonic vibration, and then dried.

[0094] S2, Matrix Cleaning:

[0095] The pretreated titanium alloy was placed into a composite magnetron sputtering deposition system, and the chamber vacuum was evacuated to 5 × 10⁻⁶. -3 Pa, then argon gas is introduced. The working pressure of high-purity argon gas is 0.5 Pa, the discharge current of hollow cathode is 60 A, the substrate bias voltage is -200 V, and the substrate workpiece is cleaned with hollow cathode plasma source for 10 min.

[0096] S3, Coating Deposition:

[0097] Adjust the working pressure of argon to 0.2 Pa, heat the substrate to 250 °C, turn on the high-power pulsed magnetron sputtering power supply, and control the operating parameters as follows: working pulse voltage of 400 V, pulse width of 300 μs, frequency of 600 Hz, and substrate bias voltage of -30 V.

[0098] A movable baffle was used to block the substrate and perform air splash self-cleaning on the Ti target. After cleaning, the baffle was removed and the Ti transition layer was deposited. The thickness of the deposited Ti transition layer was 0.45 μm.

[0099] Then, the target material was changed to Ti3SiC2 target material, the substrate temperature was kept at 250℃, the working pressure of argon gas was kept at 0.2Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 100V, pulse width of 30μs, frequency of 500Hz, substrate bias voltage of -30V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of Ti3SiC2 target material.

[0100] After cleaning, the baffle was removed and a ceramic layer with Ti3SiC2 as the main component was deposited. The thickness of the ceramic layer with Ti3SiC2 as the main component was 6μm.

[0101] Next, the target material was changed to a Ti-Si-C-Ag target with a molar ratio of Ti:Si:C:Ag = 6:1.2:1.2:4.1 prepared by hot pressing. The substrate temperature was maintained at 250℃, the working pressure of argon gas was maintained at 0.2Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 400V, pulse width of 300μs, frequency of 600Hz, substrate bias voltage of -100V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of the Ti-Si-C-Ag target.

[0102] After cleaning, the baffle was removed and a ceramic layer with Ti3(Si,Ag)C2 as the main component was deposited. The thickness of the ceramic layer with Ti3(Si,Ag)C2 as the main component was 0.5μm.

[0103] Example 4

[0104] This application provides a method for preparing a composite coating suitable for implant materials, specifically:

[0105] S1. Matrix pretreatment:

[0106] The substrate (TC4) sample was ground, polished, cleaned with alcohol and acetone by ultrasonic vibration, and then dried.

[0107] S2, Matrix Cleaning:

[0108] The pretreated titanium alloy was placed into a composite magnetron sputtering deposition system, and the chamber vacuum was evacuated to 5 × 10⁻⁶. -3 Pa, then argon gas is introduced. The working pressure of high-purity argon gas is 1 Pa, the discharge current of hollow cathode is 40 A, the substrate bias voltage is -600 V, and the substrate workpiece is cleaned for 10 min using a hollow cathode plasma source.

[0109] S3, Coating Deposition:

[0110] Adjust the working pressure of argon to 0.9 Pa, heat the substrate to 280°C, turn on the high-power pulsed magnetron sputtering power supply, and control the operating parameters as follows: working pulse voltage of 200 V, pulse width of 200 μs, frequency of 500 Hz, and substrate bias voltage of -60 V.

[0111] A movable baffle was used to block the substrate and perform air sputtering self-cleaning on the Ti target. After cleaning, the baffle was removed and the Ti transition layer was deposited, resulting in a Ti transition layer with a thickness of 0.6 μm.

[0112] Then, the target material was changed to Ti3SiC2 target material, the substrate temperature was kept at 280℃, the working pressure of argon gas was kept at 0.9Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 200V, pulse width of 100μs, frequency of 500Hz, substrate bias voltage of -60V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of Ti3SiC2 target material.

[0113] After cleaning, the baffle was removed and a ceramic layer with Ti3SiC2 as the main component was deposited, resulting in a ceramic layer with a thickness of 8 μm and Ti3SiC2 as the main component.

[0114] Next, the target material was changed to a Ti-Si-C-Ag target with a molar ratio of Ti:Si:C:Ag = 6:1.0:1.2:4.0 prepared by hot pressing. The substrate temperature was maintained at 280℃, the working pressure of argon gas was maintained at 0.2Pa, the high-power pulsed magnetron sputtering power supply was turned on, and the operating parameters were controlled as follows: working pulse voltage of 600V, pulse width of 30μs, frequency of 400Hz, substrate bias voltage of -30V, and a movable baffle was used to block the substrate to perform air sputtering self-cleaning of the Ti-Si-C-Ag target.

[0115] After cleaning, the baffle was removed and a ceramic layer with Ti3(Si,Ag)C2 as the main component was deposited, resulting in a ceramic layer with a thickness of 0.9 μm and Ti3(Si,Ag)C2 as the main component.

[0116] Comparative Example 1

[0117] This comparative example is basically the same as Example 3, except that the substrate bias voltage was set to -200V when the Ti3(Si,Ag)C2 ceramic layer was deposited. As a result, the coating mainly consisted of TiC and Ti5Si3 as well as some elemental Ag.

[0118] Comparative Example 2

[0119] This comparative example is basically the same as Comparative Example 1, except that when depositing the first ceramic layer whose main component is Ti3SiC2, the substrate bias voltage is set to -200V. As a result, the first ceramic layer of the coating prepared is mainly composed of TiC and Ti5Si3, and the composition of the second ceramic layer is the same as that of Comparative Example 1.

[0120] Comparative Example 3

[0121] This comparative example is basically the same as Example 2, except that the step of depositing a ceramic layer with Ti3(Si,Ag)C2 as the main component was not performed.

[0122] Experimental Example

[0123] The performance of the composite coatings prepared in each embodiment and comparative example was tested.

[0124] The hardness of the composite coating of the present invention was tested using a Bruker TI980 nanoindenter; the tribological properties of the composite coating of the present invention were evaluated by using GCr15 steel balls as grinding balls and conducting friction tests in simulated body fluid at room temperature; the corrosion resistance of the coating was tested using an electrochemical workstation with simulated body fluid as the corrosion solution, and the test results are shown in Table 1.

[0125] The antibacterial properties of the composite coating were compared and analyzed using the plate count method. *E. coli*, a common bacterium found in daily life, was used. The specific testing method for antibacterial properties was as follows: the antibacterial properties of the composite coating sample and the substrate were compared and analyzed using the plate count method. *E. coli* was used as the bacterial species. The coatings prepared in the examples and comparative examples were used as experimental samples, and the uncoated substrate was used as the control sample. The antibacterial test was conducted by autoclaving the control sample and the composite coating sample after cleaning with ethanol at 121°C for 20 min; the inoculated bacterial solution was diluted with physiological saline to a concentration of approximately 10%. 6 For a CFU / mL bacterial suspension, 100 μL of the diluted solution was added dropwise to a 24-well plate containing the sample. The plate was incubated at 37°C for 24 hours, and bacterial suspensions with contact times of 3, 6, 12, and 24 hours were collected. The obtained bacterial suspensions were then appropriately diluted and added dropwise to pre-sterilized solid culture medium. The bacterial suspension was then evenly spread on the surface of the medium using a spreader. The solid culture medium was incubated at 37°C for 24 hours. Finally, the number of colonies in the culture dishes was counted, and the antibacterial rate of the sample was calculated using the antibacterial formula.

[0126]

[0127] The test results are shown in Table 1 and Figure 4 As shown, Figure 4 These are comparison photos of Example 2 and the control sample.

[0128] Table 1. Performance test results of the composite coatings prepared in each embodiment and comparative example.

[0129]

[0130] As can be seen from the table above, the composite coatings prepared in each embodiment of this application exhibit good corrosion resistance, hardness, and wear resistance. Comparing Comparative Example 1 with the corresponding embodiment, the coating prepared in Comparative Example 1 shows significantly worse corrosion resistance and slightly lower antibacterial performance compared to the corresponding embodiment. This indicates that when the bias voltage is not within the range required by this application during the deposition of the second ceramic layer, the corresponding chemical composition Ti3(Si,Ag)C2 cannot be obtained; only TiC, Ti5Si3, and Ag elemental components can be obtained, resulting in a significant reduction in the coating's corrosion resistance. Furthermore, since Ag is dispersed between compounds and fails to dissolve in Ti3SiC2, its slow release is also partially affected, reducing antibacterial properties. In addition, due to the difference in composition and structure between the second ceramic layer and the first ceramic layer, the second ceramic layer is more prone to detachment during wear. As can be seen from Comparative Example 2, if the deposition bias voltage is not within the range required by this application, it is difficult to obtain a first ceramic layer with Ti3SiC2 as the main component. Its long-term friction performance will be significantly affected because the main component Ti3SiC2 is not formed, making it difficult to exert its self-lubricating properties and resulting in poor corrosion resistance. This indicates that if the coating is not deposited according to the operating parameters defined in the preferred range of this application when depositing a ceramic layer with Ti3SiC2 and Ti3(Si,Ag)C2 as the main components, the corresponding composition cannot be obtained. Consequently, it is impossible to obtain a coating with excellent comprehensive performance in terms of corrosion resistance, wear resistance, and antibacterial properties, which will affect the overall performance after titanium alloy implantation.

[0131] As can be seen from Table 1, comparing Comparative Example 3 with Example 2, the coating obtained in Example 2 exhibits significantly better antibacterial properties, indicating that the second ceramic layer, whose main component is Ti3(Si,Ag)C2, can impart antibacterial properties to the composite coating. Figure 4 As can be seen, almost no E. coli survived on the surface of the composite coating in Example 2, with an antibacterial rate >99%, while the control group showed better E. coli survival, with an antibacterial rate of only >1%. This indicates that the composite coating prepared in this application, due to its second ceramic layer with Ti3(Si,Ag)C2 as its main component, can achieve uniform and slow release of Ag, thus significantly imparting antibacterial properties to the coating.

[0132] In summary, the composite coating suitable for implant materials and its preparation method provided by this invention have the following advantages:

[0133] (1) In the composite coating of the present invention, the Ag in the Ti3(Si,Ag)C2 ceramic layer can be slowly released in the early stage of implantation to achieve excellent antibacterial properties and avoid infection of the material in the early stage of implantation.

[0134] (2) The Ti3SiC2 layer in the composite coating of the present invention has good corrosion resistance, high hardness, low friction coefficient, and self-lubricating advantage, which can enhance the corrosion resistance and wear resistance of titanium alloy implant materials during the service process in the implant.

[0135] (3) The Ti transition layer in the composite coating of the present invention can enhance the bonding force between the coating and the substrate, and promote the coating to better perform its comprehensive properties such as wear resistance, corrosion resistance and antibacterial properties.

[0136] (4) In the preferred technical solution, the preparation process of the present invention is easy to control, has good repeatability, the coating structure is controllable, the composite coating has excellent performance, meets the requirements of titanium alloy in the implantation environment, gives full play to its specific functional requirements at different stages, can improve the service life of titanium alloy implant materials, and promote the application of titanium alloy as implant materials.

[0137] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite coating suitable for implant materials, characterized in that, include: A Ti transition layer, a first ceramic layer, and a second ceramic layer are sequentially disposed on the surface of the substrate. The main component of the first ceramic layer is Ti3SiC2, and the main component of the second ceramic layer is Ti3(Si,Ag)C2.

2. The composite coating according to claim 1, characterized in that, The thickness of the Ti transition layer is 0.3–1 μm, the thickness of the first ceramic layer is 5–10 μm, and the thickness of the second ceramic layer is 0.5–1 μm.

3. The method for preparing the composite coating as described in claim 1 or 2, characterized in that, include: A Ti transition layer, a first ceramic layer with Ti3SiC2 as its main component, and a second ceramic layer with Ti3(Si,Ag)C2 as its main component are sequentially deposited on the substrate surface.

4. The preparation method according to claim 3, characterized in that, The Ti transition layer, the first ceramic layer, and the second ceramic layer are deposited using a high-power pulsed magnetron sputtering method. The target material used for depositing the Ti transition layer is a Ti target, the target material used for depositing the first ceramic layer is a Ti3SiC2 target, and the target material used for depositing the second ceramic layer is a Ti-Si-C-Ag target.

5. The preparation method according to claim 4, characterized in that, When depositing the Ti transition layer and / or the first ceramic layer whose main component is Ti3SiC2 and / or the second ceramic layer whose main component is Ti3(Si,Ag)C2 using high-power pulsed magnetron sputtering, the operating parameters are as follows: The working pulse voltage is 100–400V, the pulse width is 30–300μs, the frequency is 400–600Hz, the base bias voltage is -30–-100V, and the working pressure of argon gas is 0.2–0.9Pa. The substrate is heated to 200–300°C before deposition.

6. The preparation method according to claim 4, characterized in that, Before depositing the Ti transition layer, the substrate is cleaned using a hollow cathode plasma source. During cleaning, the working pressure of high-purity argon gas is 0.5 to 1.5 Pa, the discharge current of the hollow cathode is 30 to 60 A, and the substrate bias voltage is -200 to -600 V.

7. The preparation method according to claim 4, characterized in that, Before depositing the Ti transition layer and / or the first ceramic layer and / or the second ceramic layer, the method further includes using a movable baffle to block the substrate and perform target sputtering self-cleaning.

8. The preparation method according to claim 3, characterized in that, When depositing the second ceramic layer, the Ti-Si-C-Ag target material used is prepared by hot pressing sintering or hot isostatic pressing sintering. The molar ratio of the main components in the target material is Ti:Si:C:Ag = 6:1.0~1.2:1.0~1.2:3.6~4.

1.

9. An implantable material, characterized in that, It includes a substrate and a composite coating as described in claim 1 or 2 deposited on the surface of the substrate, or it includes a substrate and a composite coating deposited on the surface of the substrate using the preparation method described in any one of claims 3 to 8.

10. A medical device, characterized in that, Includes the implant material as described in claim 9.

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