A metal high performance coating and a process for its production

Abstract

The application belongs to the technical field of metal surface modification coating, and particularly relates to a metal high-performance coating and a preparation process thereof, wherein the coating comprises, from the surface of a metal substrate outward, a biocompatible bonding layer, a composition and structure gradient transition layer, a main functional heat insulation and anti-adhesion layer, and a surface super-hydrophobic anti-adhesion layer; the biocompatible bonding layer is composed of pure titanium or titanium alloy; the composition of the composition and structure gradient transition layer continuously and gradually changes from (Ti, Al)N or (Ti, Zr)N rich in metal to stoichiometric TiN or (Ti, Al)N along the thickness direction; the main functional heat insulation and anti-adhesion layer is an aluminum oxide (Al2O3) or yttrium oxide stabilized zirconium oxide (YSZ) layer, and the surface of the layer has a micro-nano composite rough structure; the surface super-hydrophobic anti-adhesion layer is a fluorine-containing silane coupling agent layer or a plasma polymerized perfluorocarbon layer, and the surface static water contact angle of the layer is greater than 120°.

Description

Technical Field

[0001] This invention belongs to the field of metal surface modification coating technology, specifically relating to a high-performance metal coating and its preparation process. Background Technology

[0002] In the field of energy surgery, medical metal instruments such as high-frequency electrosurgical units, radiofrequency ablation electrodes, and ultrasonic cutting hemostatic knives are core tools in clinical operations. The metal working surfaces of these instruments are in direct contact with biological tissues, and two major problems are prone to occur during energy output: First, the instrument surface adheres severely to tissues and eschars, which not only affects the smoothness of the surgical operation but also easily causes secondary tissue damage; second, the energy of the instrument is easily conducted to the surrounding healthy tissues, resulting in heat diffusion and thermal damage, which reduces the precision of the surgery.

[0003] To address these issues, existing technologies often employ a single coating to modify the surface of metal instruments, such as a simple ceramic insulation layer or a fluorocarbon anti-stick layer. However, single coatings have significant drawbacks: the ceramic layer has low bonding strength with the metal substrate, making it prone to peeling and cracking under thermal cycling and friction; the fluorocarbon anti-stick layer exhibits poor adhesion and short anti-sticking time when directly deposited on the metal surface; and a single coating cannot simultaneously achieve the comprehensive performance requirements of insulation, anti-sticking, and high bonding strength. Furthermore, some gradient coating designs only consider compositional gradients without considering the gradient control of grain size, resulting in poor thermal stress mitigation and a continued susceptibility to coating failure.

[0004] Therefore, developing a multi-layered composite metal high-performance coating with synergistic gradient control of composition and structure, possessing high bonding strength, efficient heat insulation, long-lasting non-stick properties, and excellent durability, as well as a precision preparation process adapted to this coating, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the prior art, the present invention provides a high-performance metal coating and its preparation process to solve the problems in the background art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a high-performance metal coating, wherein the coating comprises, from the surface of the metal substrate outward, a biocompatible bonding layer, a composition and structure gradient transition layer, a main functional thermal insulation and anti-adhesion layer, and a surface superhydrophobic anti-adhesion layer;

[0008] The biocompatible bonding layer is made of pure titanium or a titanium alloy;

[0009] The composition of the composition and structural gradient transition layer gradually changes along the thickness direction from metal-rich (Ti,Al)N or (Ti,Zr)N to stoichiometric TiN or (Ti,Al)N.

[0010] The main functional heat insulation and anti-adhesion layer is an alumina (Al2O3) or yttrium oxide stabilized zirconium oxide (YSZ) layer, and its surface has a micro-nano composite rough structure;

[0011] The superhydrophobic anti-stick surface is a fluorinated silane coupling agent layer or a plasma-polymerized perfluorocarbon layer, with a static water contact angle greater than 120°.

[0012] Furthermore, the pores of the main functional heat insulation and anti-adhesion layer are filled with a biocompatible lubricant, which is confined and filled into the pores by a vacuum impregnation method.

[0013] Furthermore, the biocompatible binding layer is deposited using a high-energy pulsed magnetron sputtering process, with a thickness of 0.1-0.5 micrometers.

[0014] Furthermore, the thickness of the composition and structure gradient transition layer is 2-5 micrometers, and the grain size gradually changes from nanocrystals to microcrystals along the thickness direction.

[0015] Furthermore, the composition of the micro-nano composite rough structure is consistent with the main composition of the main functional heat insulation and anti-adhesion layer. When the main functional heat insulation and anti-adhesion layer is an Al2O3 layer, the composition of the micro-nano composite rough structure is pure Al2O3 with a purity of ≥99.99%, without any other additional components. When the main functional heat insulation and anti-adhesion layer is a YSZ layer, the composition of the micro-nano composite rough structure is YSZ and Al2O3 sandblasting residue, with YSZ being the main structure.

[0016] 6. A second aspect of the present invention provides a process for preparing a high-performance metal coating, characterized by comprising the following steps:

[0017] S1: Perform composite cleaning and plasma activation on the working end of the metal substrate;

[0018] S2: The biocompatible binding layer is deposited using a high-energy pulsed magnetron sputtering process;

[0019] S3: By precisely adjusting the partial pressure of the reactive gas and the deposition parameters in real time, the composition and structural gradient transition layer is continuously deposited;

[0020] S4: The main functional thermal insulation and anti-adhesion layer is deposited using reactive magnetron sputtering, and the micro-nano composite rough structure is formed on its surface by sandblasting or plasma etching.

[0021] S5: A low-viscosity biocompatible lubricant is injected into the pores of the main functional heat insulation and anti-adhesion layer by vacuum impregnation, and the confined filling is achieved by centrifugation and heat treatment;

[0022] S6: Immerse a metal substrate with a micro-nano composite rough structure in a fluorinated silane coupling agent solution or expose it to a perfluorocarbon monomer plasma, and form the superhydrophobic anti-stick layer on the surface by thermosetting or plasma polymerization.

[0023] Furthermore, in step S1, the composite cleaning sequentially includes degreasing, acid washing, and deionized water rinsing, and the plasma activation adopts a plasma bias backsplash process with an inert gas as the working gas.

[0024] Furthermore, in step S2, a pure titanium target or a titanium alloy target is used as the sputtering source, and high-energy pulsed magnetron sputtering is performed in an inert gas atmosphere. The thickness of the bonding layer is controlled by adjusting the sputtering power and deposition time.

[0025] Furthermore, in step S3, a Ti-Al target or a Ti-Zr target is used as the sputtering source, and the deposition parameters include sputtering power and deposition temperature. The gradient changes in composition and grain size are achieved by synergistically controlling the partial pressure of the reactive gas and the deposition parameters.

[0026] Furthermore, in step S5, the vacuum degree of the vacuum impregnation is not lower than -0.09MPa, the centrifugation speed is 2000-4000r / min, the heat treatment temperature is 100-180℃, and the time is 10-30min;

[0027] In step S6, when a fluorinated silane coupling agent solution is used, chemical bonding is achieved by impregnation at room temperature followed by thermosetting at 100-180°C; when perfluorocarbon monomer plasma is used, the plasma polymerization power is 100-200W and the polymerization time is 15-30min.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Excellent performance: Through the functional synergy of the four-layer composite structure, it achieves multiple properties such as high bonding strength, efficient heat insulation, and durable superhydrophobicity and non-sticking, solving the problems of single function and insufficient performance of traditional single coatings. The biocompatible bonding layer ensures a firm bond between the coating and the substrate, the gradient transition layer mitigates thermal stress and prevents crack propagation, the main functional layer provides heat insulation and provides an anchoring interface, and the superhydrophobic layer achieves non-sticking. The cooperation of each layer greatly improves the performance of metal instruments.

[0030] 2. Long-lasting and stable anti-adhesion effect: The superhydrophobic anti-adhesion layer is chemically bonded to the rough main functional layer surface, with strong adhesion. The lubricant filled in the pores of the main functional layer generates a dynamic self-lubricating effect when heated, which synergizes with the superhydrophobic properties, significantly reducing the adhesion of tissue and eschar. Moreover, the anti-adhesion effect is not easily diminished under thermal cycling and friction.

[0031] 3. Precise thermal insulation, reducing thermal damage: The main functional thermal insulation and anti-adhesion layer uses Al2O3 or YSZ ceramic materials with low thermal conductivity and a preferred oriented columnar crystal structure, which can effectively focus energy, reduce the thermal diffusion of energy to surrounding healthy tissues, improve the precision of surgical operations, and reduce the risk of clinical thermal damage.

[0032] 4. High durability and reliability: The gradient transition layer of composition and structure achieves gradient matching of thermal expansion coefficient and gradient control of grain size, effectively suppressing the generation and propagation of cracks inside the coating; the layers are firmly bonded through mechanical interlocking or chemical bonding, making the coating less prone to peeling and cracking under conditions such as thermal cycling, friction, and impact, thus greatly extending the service life of metal instruments.

[0033] 5. Good biocompatibility and safety: All materials in each layer of the coating meet medical biocompatibility standards, with no toxic or harmful substances released, and antibacterial functions can be selected according to clinical needs to further reduce the risk of surgical infection; the entire preparation process generates no harmful pollutants and meets the requirements of green production.

[0034] 6. Strong process adaptability: The preparation process steps are precise and controllable. Each deposition and modification process is applicable to the surface of metal instruments with complex curved surfaces and precision structures. It can achieve uniform deposition of coatings and ensure the consistency of coating performance. It can be widely used in the surface modification of various medical energy surgical metal instruments. Attached Figure Description

[0035] Figure 1 This is a process flow diagram for preparing a high-performance metal coating according to the present invention; Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0038] To achieve the above objectives, the present invention provides a high-performance metal coating, wherein the coating comprises, from the surface of the metal substrate outwards, a biocompatible bonding layer, a composition and structure gradient transition layer, a primary functional thermal insulation and anti-adhesion layer, and a surface superhydrophobic anti-adhesion layer, and the structure and parameters of each layer are as follows:

[0039] 1. Biocompatible bonding layer: Composed of pure titanium or titanium alloy, it is deposited on the surface of the metal substrate by high-energy pulsed magnetron sputtering process, with a thickness of 0.1-0.5 micrometers. It is used to achieve high bonding strength between the coating and the metal substrate, while having good biocompatibility and meeting medical standards.

[0040] 2. Composition and structure gradient transition layer: The thickness is 2-5 micrometers. Its composition gradually changes from metal-rich (Ti,Al)N or (Ti,Zr)N to stoichiometric TiN or (Ti,Al)N along the thickness direction. The grain size gradually changes from nanocrystals to microcrystals along the thickness direction. It is used to match the thermal expansion coefficients of the metal substrate and the outer coating, alleviate thermal stress, and prevent cracks from propagating inside the coating.

[0041] 3. Main functional thermal insulation and anti-adhesion layer: The thickness is 3-10 micrometers. It is an alumina (Al2O3) or yttrium-stabilized zirconia (YSZ) layer with a preferred orientation columnar crystal structure, which is prepared by physical vapor deposition. Its surface has a micro-nano composite rough structure of 0.3-1.2 micrometers. This layer achieves efficient thermal insulation, reduces the thermal diffusion of energy to the surrounding tissue, and provides an anchoring interface for the superhydrophobic anti-adhesion layer on the surface, thereby improving the interlayer bonding force.

[0042] 4. Superhydrophobic anti-sticking layer: The thickness is 0.05-0.5 micrometers. It is a fluorinated silane coupling agent layer or plasma-polymerized perfluorocarbon layer that is fixed to the rough surface of the main functional heat insulation and anti-sticking layer by chemical bonding. Its surface static water contact angle is greater than 120°, which is used to significantly reduce the adhesion of tissue and eschar to the coating surface and achieve a superhydrophobic anti-sticking effect.

[0043] Furthermore, the pores of the main functional heat insulation and anti-sticking layer are filled with a low-viscosity biocompatible lubricant. The lubricant is confined and filled into the pores by vacuum impregnation, and can generate a dynamic self-lubricating effect when heated, further improving the anti-sticking performance.

[0044] The present invention also provides a preparation process for the above-mentioned high-performance metal coating, comprising the following steps:

[0045] S1: Perform composite cleaning and plasma activation on the working end of the metal substrate; perform composite cleaning by degreasing, pickling, and rinsing with deionized water in sequence. After drying, place the metal substrate in a vacuum chamber and perform surface activation by plasma bias backsplashing process to remove residual impurities on the surface and improve the surface activity of the substrate.

[0046] S2: A biocompatible bonding layer is deposited using a high-energy pulsed magnetron sputtering process; a pure titanium target or a titanium alloy target is used as the sputtering source, and high-energy pulsed magnetron sputtering is performed in an inert gas atmosphere. The sputtering power and deposition time are controlled to form a 0.1-0.5 micrometer thick pure titanium or titanium alloy bonding layer on the surface of the metal substrate.

[0047] S3: Continuous deposition of a gradient transition layer of composition and structure; by real-time precise adjustment of parameters such as the partial pressure of the reactive gas (nitrogen), sputtering power, and deposition temperature, using a Ti-Al target or a Ti-Zr target as the sputtering source, a continuous gradient change in composition is achieved from metal-rich (Ti,Al)N or (Ti,Zr)N to stoichiometric TiN or (Ti,Al)N. At the same time, the grain growth rate is controlled to achieve a gradient change in grain size from nanocrystals to microcrystals, depositing a gradient transition layer of 2-5 micrometers thick.

[0048] S4: Deposit the main functional thermal insulation and anti-adhesion layer and construct a micro-nano composite rough structure; using reactive magnetron sputtering, with an aluminum target or a zirconium-yttrium composite target as the sputtering source, control the preferred growth direction of columnar crystals in an oxidizing atmosphere to deposit an Al2O3 or YSZ layer with a thickness of 3-10 micrometers; then construct a micro-nano composite rough structure of 0.3-1.2 micrometers on the surface of this layer by sandblasting or plasma etching.

[0049] S5: Confined filling with biocompatible lubricant; The metal substrate treated in step S4 is placed in a low-viscosity biocompatible lubricant, and the lubricant is penetrated into the pores of the main functional heat insulation and anti-adhesion layer by vacuum impregnation. Then, centrifugation is performed to remove excess lubricant from the surface, and heat treatment is performed to achieve confined fixation of the lubricant in the pores.

[0050] S6: Prepare a superhydrophobic anti-sticking layer; immerse a metal substrate with a micro-nano composite rough structure in a fluorinated silane coupling agent solution and achieve chemical bonding through thermosetting, or expose it to perfluorocarbon monomer plasma and form a perfluorocarbon layer through plasma polymerization; finally, a superhydrophobic anti-sticking layer with a thickness of 0.05-0.5 micrometers and a static water contact angle greater than 120° is formed.

[0051] Example 1

[0052] A high-performance metallic coating suitable for radiofrequency ablation electrodes, comprising, from the surface of the titanium alloy electrode substrate outwards:

[0053] 1. Biocompatible bonding layer: pure titanium layer, 0.3 micrometers thick, deposited by high-energy pulsed magnetron sputtering process;

[0054] 2. Composition and structure gradient transition layer: 3 micrometers thick, with composition gradually changing from metal-rich (Ti,Al)N to stoichiometric TiN, and grain size gradually changing from 20nm nanocrystals to 1μm microcrystals;

[0055] 3. Main functional heat insulation and anti-adhesion layer: Al2O3 layer, 6 micrometers thick, with a preferred orientation columnar crystal structure and a surface micro-nano composite rough structure with a size of 0.8 micrometers;

[0056] 4. Superhydrophobic anti-sticking layer: Fluorosilane coupling agent layer, 0.2 micrometers thick, with a static water contact angle of 135°;

[0057] The pores of the main functional heat insulation and anti-adhesion layer are filled with medical-grade polyethylene glycol lubricant.

[0058] The preparation process of the above coating includes the following steps:

[0059] S1: The exposed conductive part of the titanium alloy radiofrequency ablation electrode is cleaned in a composite manner, and is then degreased with medical degreasing agent, acid washed with 5% dilute hydrochloric acid, rinsed with deionized water, dried with nitrogen, and placed in a vacuum chamber. It is then activated by Ar plasma bias backsputtering with a backsputtering bias of -250V for 15 minutes.

[0060] S2: Using a 99.99% pure titanium target as the sputtering source, a pure titanium bonding layer was deposited by high-energy pulsed magnetron sputtering in an Ar atmosphere. The pulse power was 300W and the deposition time was 20min, forming a bonding layer with a thickness of 0.3 micrometers.

[0061] S3: Using a Ti-Al alloy target (Ti:Al=7:3) as the sputtering source, the N2 partial pressure was adjusted in real time from 0.1Pa to 0.5Pa, the sputtering power was adjusted from 250W to 400W, the deposition temperature was 300℃, and continuous deposition was carried out for 30min to form a 3-micron thick composition and structure gradient transition layer.

[0062] S4: Using a 99.99% aluminum target as the sputtering source, reactive magnetron sputtering is employed, introducing a mixed gas of O2 and Ar to control the preferential growth of columnar crystals along the direction perpendicular to the substrate. The deposition time is 60 minutes, forming a 6-micrometer-thick Al2O3 layer. Subsequently, a plasma etching process is used for 8 minutes to form a 0.8-micrometer-thick micro-nano composite rough structure on the surface. The composition of the micro-nano composite rough structure is consistent with the main functional heat insulation and anti-adhesion layer, which is pure Al2O3 (purity ≥99.99%), without any other additional components. Its microscopic protrusions are Al2O3 columnar crystal protrusions, and the recessed parts are Al2O3 pores formed after etching. The volume ratio of protrusions to recesses is approximately 3:2, ensuring the stability and anchoring effect of the rough structure.

[0063] S5: The electrode is placed in medical polyethylene glycol lubricant (viscosity 20 mPa·s), vacuum impregnated for 30 min at a vacuum degree of -0.09 MPa, then centrifuged at 3000 r / min for 10 min, and then heat-treated at 120℃ for 20 min to achieve confined filling of the lubricant.

[0064] S6: Immerse the electrode in a 5% (w / w) ethanol solution of fluorinated silane coupling agent and soak at room temperature for 2 hours, then heat cure at 150°C for 30 minutes to form a 0.2-micron thick superhydrophobic anti-stick layer of fluorinated silane coupling agent.

[0065] Tests showed that the coating bonded to the titanium alloy substrate with a strength greater than 50 N, the coating thermal conductivity was 0.8 W / (m·K), the surface static water contact angle was 135°, and after 100 cycles of thermal cycling (-20℃ to 200℃), the coating showed no cracking or peeling, and its anti-stick performance did not significantly decrease.

[0066] Example 2

[0067] A high-performance metallic coating suitable for ultrasonic cutting hemostatic scalpel tips, comprising the following components from the stainless steel tip substrate surface outwards:

[0068] 1. Biocompatible bonding layer: Ti6Al4V titanium alloy layer, 0.5 micrometers thick, deposited by high-energy pulsed magnetron sputtering process;

[0069] 2. Composition and structural gradient transition layer: 5 micrometers thick, with composition gradually changing from metal-rich (Ti,Zr)N to stoichiometric (Ti,Al)N, and grain size gradually changing from 30 nm nanocrystals to 1.2 μm microcrystals;

[0070] 3. Main functional heat insulation and anti-adhesion layer: YSZ layer, 10 micrometers thick, with a preferred orientation columnar crystal structure and a surface micro-nano composite rough structure with a size of 1.2 micrometers;

[0071] 4. Superhydrophobic anti-sticking layer: Plasma-polymerized perfluorocarbon layer, 0.5 micrometers thick, with a static water contact angle of 140°;

[0072] The pores of the main functional heat insulation and anti-adhesion layer are filled with medical-grade polysiloxane lubricant.

[0073] The preparation process of the above coating includes the following steps:

[0074] S1: Perform a composite cleaning on the working surface of the stainless steel ultrasonic scalpel head, using alkaline degreasing agent, 10% dilute sulfuric acid pickling, deionized water rinsing, nitrogen blowing to dry, and then place it in a vacuum chamber. Activate it with Ar plasma bias backsputtering at a backsputtering bias of -300V for 20 minutes.

[0075] S2: Using a Ti6Al4V titanium alloy target as the sputtering source, a titanium alloy bonding layer was deposited by high-energy pulsed magnetron sputtering in an Ar atmosphere. The pulse power was 400W and the deposition time was 30min, forming a bonding layer with a thickness of 0.5 micrometers.

[0076] S3: Using a Ti-Zr alloy target (Ti:Zr=6:4) and a Ti-Al alloy target (Ti:Al=8:2) as dual sputtering sources, the N2 partial pressure was adjusted in real time from 0.2Pa to 0.6Pa, the sputtering power of the two targets was adjusted in a coordinated manner, the deposition temperature was 350℃, and continuous deposition was carried out for 50min to form a 5-micron thick composition and structure gradient transition layer.

[0077] S4: Using a Zr-Y composite target (ZrO2:Y2O3=92:8) as the sputtering source, reactive magnetron sputtering was employed, introducing a mixed gas of O2 and Ar to control the preferential growth of columnar crystals. The deposition time was 100 min, forming a 10 μm thick YSZ layer. Subsequently, a sandblasting process was used with 50 nm Al2O3 micropowder as the sandblasting medium and a sandblasting pressure of 0.2 MPa to form a 1.2 μm micro-nano composite rough structure on the surface. The micro-nano composite rough structure consists of YSZ (ZrO2:Y2O3=92:8) and a small amount of attached Al2O3 sandblasting medium, wherein the proportion of YSZ is ≥98% and the proportion of Al2O3 sandblasting medium is ≤2% (a small amount of residue from the sandblasting process that does not affect the structural performance). Microscopically, YSZ forms a continuous rough substrate, and the residual Al2O3 fills the fine pores, further optimizing the rough morphology.

[0078] S5: Place the blade in medical polysiloxane lubricant (viscosity 30 mPa·s), vacuum impregnate for 40 min at a vacuum degree of -0.095 MPa, then centrifuge at 4000 r / min for 15 min, and then heat treat at 150℃ for 30 min to achieve confined filling of the lubricant.

[0079] S6: Place the cutter head in the vacuum plasma chamber, introduce perfluorooctyl vinyl ether monomer, plasma polymerization power 150W, polymerization time 25min, to form a 0.5 micrometer thick plasma-polymerized perfluorocarbon superhydrophobic non-stick layer.

[0080] Tests showed that the coating bonded to the stainless steel substrate with a strength greater than 45 N, the coating thermal conductivity was 0.6 W / (m·K), the static water contact angle was 140°, and after 200 friction tests (load 5 N), the coating showed no wear or peeling, and its anti-stick properties remained good.

[0081] Comparative Example 1

[0082] A coating for a radiofrequency ablation electrode comprises, from the surface of a titanium alloy electrode substrate outwards: a pure titanium bonding layer (0.3 μm thick), an Al2O3 main functional heat insulation and anti-adhesion layer (6 μm thick, with a surface micro-nano rough structure of 0.8 μm), and a fluorinated silane coupling agent superhydrophobic anti-adhesion layer (0.2 μm thick), with the pores of the main functional layer filled with medical polyethylene glycol lubricant.

[0083] The preparation process is completely identical to that of Example 1, except that step S3 (depositing the composition and structure gradient transition layer) is omitted.

[0084] Testing revealed that the coating's bonding strength with the titanium alloy substrate was 28 N, its thermal conductivity was 0.9 W / (m·K), and its static water contact angle was 132°. After 50 cycles of thermal cycling (from -20°C to 200°C), the coating showed obvious cracking and localized peeling, with its anti-sticking performance decreasing by 35%.

[0085] Comparative Example 2

[0086] A coating for radiofrequency ablation electrodes consists of a 0.2-micrometer-thick fluorinated silane coupling agent anti-sticking layer deposited only on the surface of a titanium alloy electrode substrate, without a bonding layer, a gradient transition layer, or a primary functional heat insulation and anti-sticking layer.

[0087] Preparation process: Only the titanium alloy substrate is subjected to composite cleaning and plasma activation (same as step S1 in Example 1), and then the operation of step S6 in Example 1 is directly performed to prepare the anti-sticking layer.

[0088] Testing revealed that the coating's bonding strength with the titanium alloy substrate was only 12N, with no significant heat insulation effect (the thermal conductivity was consistent with the titanium alloy substrate, approximately 17W / (m·K)). The surface static water contact angle was 115°. After 10 cycles of hot and cold, the coating peeled off over a large area. After 20 friction tests, the anti-stick layer was completely worn away, losing its anti-stick effect.

[0089] Comparative Example 3

[0090] A coating for radio frequency ablation electrodes has a structure that is completely consistent with that of Example 1, except that the surface of the main functional heat insulation and anti-adhesion layer does not have a 0.3-1.2 micrometer micro-nano composite rough structure (the plasma etching step is omitted in step S4 of the preparation process).

[0091] Except for step S4, which omits plasma etching and does not construct micro-nano rough structures, the fabrication process is completely consistent with that of Example 1.

[0092] The coating was tested and found to have a bonding strength of 42 N with the titanium alloy substrate, a thermal conductivity of 0.85 W / (m·K), a static water contact angle of 98°, and no obvious cracking after 80 cycles of thermal cycling. However, the anti-sticking performance decreased by 40%, and the adhesion to the substrate was improved by 60% compared with Example 1.

[0093] Based on the test results of Examples 1 and 2 and Comparative Examples 1, 2, and 3 above, the technical advantages of the present invention are analyzed in detail, clarifying the key influences of each structural layer and process step on the coating performance:

[0094] 1. The Key Role of the Gradient Transition Layer: Comparing Example 1 and Comparative Example 1, it can be seen that without the compositional and structural gradient transition layer, the bonding strength between the coating and the substrate decreased from greater than 50 N to 28 N, a decrease of 44%; the thermal cycling stability decreased significantly, with the number of cycles for cracking and delamination decreasing from 100 to 50; and the thermal conductivity increased slightly (from 0.8 W / (m·K) to 0.9 W / (m·K)). The core reason is that the gradient transition layer, through gradient regulation of composition (metal-rich phase → stoichiometric phase) and grain size (nanocrystalline → microcrystalline), achieves a smooth transition of the coefficient of thermal expansion between the metal substrate and the ceramic main functional layer, effectively mitigating the thermal stress generated during thermal cycling, preventing crack initiation and propagation, and simultaneously improving interlayer bonding strength. This proves that the gradient transition layer is one of the core structures ensuring high bonding strength and high durability of the coating.

[0095] 2. Synergistic Advantages of Multi-Layer Composite Structure: Comparing Example 1 and Comparative Example 2 (single anti-stick coating), it is evident that a single anti-stick coating completely fails to achieve the comprehensive performance of this invention—the bonding strength is only 24% of that of Example 1, it has no thermal insulation effect (thermal conductivity is much higher than Example 1), the static water contact angle does not meet the superhydrophobic standard (<120°), and its durability is extremely poor (it fails after 10 cycles of hot and cold cycling and 20 cycles of friction). In contrast, the four-layer composite structure of this invention (bonding layer + gradient transition layer + main functional layer + superhydrophobic layer) achieves functional synergy: the bonding layer ensures basic bonding strength and biocompatibility, the gradient transition layer enhances stability, the main functional layer provides efficient thermal insulation and an anchoring interface, and the superhydrophobic layer provides anti-sticking. The layers work together to solve the technical pain points of traditional single coatings—limited functionality and insufficient performance—and achieve multiple performance goals: "high bonding strength + efficient thermal insulation + durable anti-sticking."

[0096] 3. Importance of the micro-nano roughening structure of the main functional layer: Comparing Example 1 and Comparative Example 3, it can be seen that after the main functional layer lacks the micro-nano composite roughening structure, the static water contact angle of the coating surface decreases from 135° to 98°, losing its superhydrophobic properties; the anti-sticking performance decreases by 40%, while the tissue adhesion is improved by 60% compared to Example 1. In Example 1, the micro-nano composite roughening structure is composed of pure Al2O3 (purity ≥99.99%), with no other components, and the volume ratio of protrusions to depressions is approximately 3:2; in Example 2, the micro-nano composite roughening structure is composed of YSZ (ZrO2:Y2O3=92:8) and ≤2% Al2O3 sandblasting residue, with YSZ as the main structure. The composition of this structure matches the main components of the main functional layer, which can avoid poor interlayer bonding caused by compositional differences. Its proportional design can ensure the microstructure required for superhydrophobicity and provide sufficient anchoring sites for the superhydrophobic anti-stick layer, enhance the chemical bonding strength between the superhydrophobic layer and the main functional layer, and at the same time construct the surface microstructure required for superhydrophobicity. Combined with the self-lubricating effect of the lubricant, a long-lasting and stable anti-stick effect can be achieved. If this structure is missing, the superhydrophobic layer will not be firmly bonded, and the anti-stick performance will deteriorate rapidly.

[0097] 4. Overall Process Adaptability: Examples 1 and 2 employ a complete preparation process (composite cleaning and activation → bonding layer deposition → gradient transition layer deposition → main functional layer deposition + roughening → lubricant filling → superhydrophobic layer preparation). Each step works in synergy to ensure uniform and strong bonding of the coating layers and stable performance. In contrast, Comparative Examples 1, 2, and 3 omit key process steps (missing gradient transition layer deposition, omitting roughening treatment, and omitting multi-layer deposition), resulting in a comprehensive decline in coating performance. Furthermore, Example 2, by adjusting the bonding layer material (Ti6Al4V titanium alloy) and sputtering source parameters for a stainless steel substrate, still achieves excellent performance, demonstrating the good adaptability of the preparation process of this invention, making it suitable for different types of metal substrates.

[0098] In summary, this invention effectively solves the problems of low coating bonding strength, short anti-sticking time, poor heat insulation effect, and insufficient durability in the prior art by designing a multi-layer composite structure, gradient control of composition and structure, and supporting precision preparation process. Each structural layer and process step works together to achieve a comprehensive performance improvement of the high-performance metal coating. Compared with existing single coatings or coatings lacking key structures, it has significant technical advantages and practicality.

[0099] The above are merely embodiments of the present invention. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The scope of protection in this application does not involve improvements to the software and methods. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A high-performance metal coating, characterized in that: The coating, from the surface of the metal substrate outwards, includes a biocompatible bonding layer, a composition and structure gradient transition layer, a main functional thermal insulation and anti-adhesion layer, and a surface superhydrophobic anti-adhesion layer. The biocompatible bonding layer is made of pure titanium or a titanium alloy; The composition of the composition and structural gradient transition layer gradually changes along the thickness direction from metal-rich (Ti,Al)N or (Ti,Zr)N to stoichiometric TiN or (Ti,Al)N. The main functional heat insulation and anti-adhesion layer is an alumina (Al2O3) or yttrium oxide stabilized zirconium oxide (YSZ) layer, and its surface has a micro-nano composite rough structure; The superhydrophobic anti-stick surface is a fluorinated silane coupling agent layer or a plasma-polymerized perfluorocarbon layer, with a static water contact angle greater than 120°.

2. The high-performance metal coating as described in claim 1, characterized in that: The pores of the main functional heat insulation and anti-adhesion layer are filled with a biocompatible lubricant, which is confined and filled into the pores by a vacuum impregnation method.

3. The high-performance metal coating as described in claim 1, characterized in that: The biocompatible binding layer is deposited using a high-energy pulsed magnetron sputtering process and has a thickness of 0.1-0.5 micrometers.

4. The high-performance metal coating as described in claim 1, characterized in that: The thickness of the composition and structure gradient transition layer is 2-5 micrometers, and the grain size gradually changes from nanocrystals to microcrystals along the thickness direction.

5. The high-performance metal coating as described in claim 1, characterized in that: The composition of the micro-nano composite rough structure is consistent with the main composition of the main functional heat insulation and anti-adhesion layer. When the main functional heat insulation and anti-adhesion layer is an Al2O3 layer, the composition of the micro-nano composite rough structure is pure Al2O3 with a purity of ≥99.99% and no other additional components. When the main functional heat insulation and anti-adhesion layer is a YSZ layer, the composition of the micro-nano composite rough structure is YSZ and Al2O3 sandblasting residue, with YSZ being the main structure.

6. A process for preparing a high-performance metal coating as described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Perform composite cleaning and plasma activation on the working end of the metal substrate; S2: The biocompatible binding layer is deposited using a high-energy pulsed magnetron sputtering process; S3: By precisely adjusting the partial pressure of the reactive gas and the deposition parameters in real time, the composition and structural gradient transition layer is continuously deposited; S4: The main functional thermal insulation and anti-adhesion layer is deposited using reactive magnetron sputtering, and the micro-nano composite rough structure is formed on its surface by sandblasting or plasma etching. S5: A low-viscosity biocompatible lubricant is injected into the pores of the main functional heat insulation and anti-adhesion layer by vacuum impregnation, and the confined filling is achieved by centrifugation and heat treatment; S6: Immerse a metal substrate with a micro-nano composite rough structure in a fluorinated silane coupling agent solution or expose it to a perfluorocarbon monomer plasma, and form the superhydrophobic anti-stick layer on the surface by thermosetting or plasma polymerization.

7. The preparation process of a high-performance metal coating as described in claim 6, characterized in that: In step S1, the composite cleaning sequentially includes degreasing, acid washing, and deionized water rinsing. The plasma activation adopts a plasma bias backsplash process with an inert gas as the working gas.

8. The preparation process of a high-performance metal coating as described in claim 6, characterized in that, In step S2, a pure titanium target or a titanium alloy target is used as the sputtering source, and high-energy pulsed magnetron sputtering is performed in an inert gas atmosphere. The thickness of the bonding layer is controlled by adjusting the sputtering power and the deposition time.

9. The preparation process of a high-performance metal coating as described in claim 6, characterized in that: In step S3, a Ti-Al target or a Ti-Zr target is used as the sputtering source. The deposition parameters include sputtering power and deposition temperature. Gradient changes in composition and grain size are achieved by synergistically controlling the partial pressure of the reactive gas and the deposition parameters.

10. The preparation process of a high-performance metal coating as described in claim 6, characterized in that: In step S5, the vacuum degree of the vacuum impregnation is not lower than -0.09MPa, the centrifugation speed is 2000-4000r / min, the heat treatment temperature is 100-180℃, and the time is 10-30min; In step S6, when a fluorinated silane coupling agent solution is used, chemical bonding is achieved by impregnation at room temperature followed by thermosetting at 100-180°C; when perfluorocarbon monomer plasma is used, the plasma polymerization power is 100-200W and the polymerization time is 15-30min.

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