A metal substrate having a polymer coating and a method of making the same

Abstract

The present application relates to a metal substrate with polymer coating, comprising a metal base layer and a polymer coating layer covering the metal base layer, wherein the metal base layer comprises a micro-nano structure surface layer, the micro-nano structure surface layer comprises a micro-level convex primary structure and a nano-level convex secondary structure distributed on the micro-level convex primary structure, and the micro-nano structure surface layer is covered by the polymer coating layer. Through the secondary structure feature, the bonding strength of the polymer coating on the metal base can be greatly enhanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal substrate surface treatment, and particularly relates to a metal substrate with a polymer coating and a preparation method thereof. BACKGROUND

[0002] Generally, the surface of a metal substrate needs to be coated with a polymer coating to play the functions of corrosion resistance, oxidation resistance, wear resistance enhancement of the metal, etc. In addition, the polymer coating can increase the chemical stability, resist the erosion of many chemicals, and protect the metal substrate from damage by chemicals. Among them, epoxy resin, polyurethane, fluorine-containing resin, acrylic resin, silicone resin, etc. are common polymer coating materials.

[0003] However, due to the large difference in physical and chemical properties between the polymer and the metal material, the polymer coating coated on the surface of the metal substrate often has the problem of low bonding strength. Taking fluorine resin as an example, it has strong chemical inertness, so the bonding strength of the coating layer prepared under conventional conditions is very low, and the commonly used polytetrafluoroethylene coating firmness improvement schemes in the prior art all have certain limitations. Chemical corrosion modification needs to use organic metal reagents, and the related reagents are flammable and the treatment of waste liquid pollutes the environment to a large extent; irradiation modification and corona modification need to use special equipment, and the treatment process easily reduces the mechanical properties of the polytetrafluoroethylene coating and produces fluorine ions and fluorine-containing organic small molecules in the treatment process, which poses a certain harm to the life and health of the operators. In addition, the methods of chemical corrosion modification, irradiation modification, corona modification, etc. all increase the surface energy of the polytetrafluoroethylene coating by destroying the original molecular structure of the polytetrafluoroethylene, which reduces the chemical stability of the polytetrafluoroethylene coating.

[0004] Therefore, how to improve the bonding strength of the polymer coating on the surface of the metal substrate and avoid the peeling of the polymer coating has become a technical problem to be solved at present. SUMMARY

[0005] The problem to be solved by the invention

[0006] To solve the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a metal substrate with a polymer coating, which comprises a metal substrate layer and a polymer coating covering the metal substrate layer, the metal substrate layer comprises a micro-nano structure surface layer, the micro-nano structure surface layer comprises a micron-level protruding primary structure and a nano-level protruding secondary structure distributed on the micron-level protruding primary structure, and the micro-nano structure surface layer is covered by the polymer coating. Through this secondary structure feature, the bonding strength of the polymer coating on the metal substrate can be greatly enhanced.

[0007] The solution to the problem

[0008] The present application provides a metal substrate with a polymer coating, comprising a metal base layer, and a polymer coating layer covering the metal base layer, characterized in that the metal base layer comprises a micro-nano structure surface layer, the micro-nano structure surface layer comprises a micro-level convex primary structure and a nano-level convex secondary structure distributed on the micro-level convex primary structure, and the micro-nano structure surface layer is covered by the polymer coating layer.

[0009] Further, the metal comprises stainless steel, magnesium alloy, metallic aluminum, titanium alloy, nickel-based alloy, cobalt-chromium alloy and noble metal alloy.

[0010] Further, the polymer coating is a resin coating, selected from one or more of epoxy resin, fluorine-containing resin, polyurethane resin, acrylic resin, polyester resin, and silicone resin; preferably fluorine-containing resin.

[0011] Further, the polymer coating has a coating firmness of 4B and above, determined by the cross-hatch test method.

[0012] Further, the metal substrate with a polymer coating is a medical device.

[0013] Further, the metal substrate with a polymer coating is a vehicle. Preferably a ship, a vehicle, an aircraft.

[0014] The present application also provides a preparation method of the aforementioned metal substrate with a polymer coating, comprising the following steps:

[0015] Providing a metal base;

[0016] First polishing the metal base with polishing material having a first grit to form a primary structure;

[0017] Second polishing the metal base with polishing material having a second grit to form a secondary structure;

[0018] Coating a polymer coating layer on the metal base with the secondary structure polished;

[0019] And wherein the second grit is more than ten times the first grit.

[0020] Further, the first grit is at least 40 and the second grit is not more than 2000.

[0021] Further, the metal comprises stainless steel, magnesium alloy, metallic aluminum, titanium alloy, nickel-based alloy, cobalt-chromium alloy and noble metal alloy.

[0022] Further, the polymer coating is a resin coating, selected from one or more of epoxy resin, fluorine-containing resin, polyurethane resin, acrylic resin, polyester resin, and silicone resin; preferably fluorine-containing resin.

[0023] Further, the direction of the first polishing with the polishing material with the first sand purpose and the second polishing with the polishing material with the second sand purpose is consistent.

[0024] Further, the polishing material is a material with a certain abrasive particle size, including one or more of sandpaper, sand cloth, sand belt, and sand wheel.

[0025] Effects of the invention

[0026] Compared with the prior art, the technical scheme has the following innovations:

[0027] 1) The method for improving the firmness of the polymer coating by using the secondary structure is simple to operate, only two different specifications of polishing materials are needed, and no special equipment and special chemical reagents are needed.

[0028] 2) The method for improving the firmness of the polymer coating by using the secondary structure does not need to destroy the molecular structure of the polymer, and the good chemical stability of the polymer coating is retained, and it is especially suitable for fluorine-containing coatings.

[0029] 3) The method for improving the firmness of the polymer coating by using the secondary structure can be applied to various metal substrates.

[0030] 4) For fluorine-containing coatings, the method for improving the firmness by using the secondary structure can avoid the generation of fluorine-containing by-products during the treatment process, and has good environmental friendliness. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The surface three-dimensional topography of the micro-nano structure surface layer formed on the stainless steel substrate in the preparation method provided for the embodiments (comparative example 1, comparative example 4, and example 10) of the present application. DETAILED DESCRIPTION

[0032] In order to better illustrate the present application, numerous specific details are given in the following detailed description. Those skilled in the art will understand that the present application can be implemented without certain specific details. In some other examples, methods, means, apparatus and steps that are well known to those skilled in the art are not described in detail, in order to highlight the main idea of the present application.

[0033] Unless otherwise defined, the technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0034] In the present specification, the numerical range represented by "numerical value A~numerical value B" means a range including the end point values A and B.

[0035] In the present specification, the meaning indicated by "can" includes both the meaning of performing a certain process and the meaning of not performing the certain process.

[0036] It should be understood that the use of the singular form "a" or "an" or "the" in the application and the appended claims includes the plural form unless the context clearly dictates otherwise.

[0037] In the present specification, the terms "one or more specific / preferred embodiments / aspect", "another or more specific / preferred embodiments / aspect", "one or another embodiment / aspect", "one or another technical solution" and the like mean that the specific element (for example, features, structures, properties and / or characteristics) described in relation to the embodiment is included in at least one embodiment described herein, and can be present in other embodiments or can not be present in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0038] The term "comprising" and its variants, such as "comprise" and "comprises", in the specification and claims of the present application are intended to cover the process, method, product, or apparatus without excluding other steps, elements, or components. For example, a process, method, product, or apparatus that comprises a list of steps or elements is not limited to the listed steps or elements, but can optionally include additional steps or elements not expressly listed or inherent to such process, method, product, or apparatus.

[0039] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or a specific number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the invention, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise specifically limited. In the description of the invention, the meaning of "several" is at least one, for example, one, two, etc., unless otherwise specifically limited.

[0040] Figure 1 The surface three-dimensional topography of the micro-nano structured surface layer formed on the stainless steel substrate in the preparation method provided by the present application (Comparative Example 1, Comparative Example 4, Example 10). The present application provides a metal substrate with a polymer coating layer, which comprises a metal substrate layer, and a polymer coating layer covering the metal substrate layer, characterized in that the metal substrate layer comprises a micro-nano structured surface layer, the micro-nano structured surface layer comprises a primary structure and a secondary structure distributed on the primary structure, and the micro-nano structured surface layer is covered by the polymer coating layer.

[0041] The primary structure in the application is a micron-level protruding structure, and the secondary structure is a nanometer-level protruding structure and is distributed on the micron-level protruding primary structure; the size of the secondary structure is smaller than that of the primary structure.

[0042] Specifically, the secondary structure formed by polishing on the metal substrate is formed on the primary structure, and the size is significantly smaller than that of the primary structure, which can greatly increase the specific surface area to improve the adhesion of the subsequent coating.

[0043] The primary structure and the secondary structure in the application are both formed by physical polishing of the metal substrate itself, which is different from the schemes such as sandblasting on the metal surface, adhesion of nanoparticles or chemical reagent treatment. The micro-nano structure composition in the application is consistent with the substrate, and will not damage the chemical composition of the substrate surface, and does not require special equipment and special chemical reagents.

[0044] In the application, the metal substrate can be any metal material that can be polished, including but not limited to stainless steel, magnesium alloy, metal aluminum, titanium alloy, nickel-based alloy, cobalt-chromium alloy and noble metal alloy.

[0045] In the application, the polymer coating is a resin coating material, and the resin coating material has various functions and plays an important role in the fields of medical treatment, industry, aerospace, ships and other vehicles, building, machinery manufacturing, etc. According to the specific application requirements, selecting appropriate types of resin coating can greatly improve the functionality of the product, including but not limited to epoxy resin, fluorine-containing resin, polyurethane resin, acrylic resin, polyester resin, and silicone resin. For example, PTFE and other fluorine-containing coatings have very low friction coefficient, excellent chemical inertness and corrosion resistance, excellent electrical insulation and high temperature resistance and weather resistance, and are therefore very suitable for high-performance metal materials such as medical device products and aerospace. However, because PTFE and other fluorine-containing coatings have high chemical inertness and are not easy to chemically react with other substances, and the surface energy is very low, it is difficult to form effective physical or chemical adhesion with other substances. The primary structure and the secondary structure of the metal substrate surface provided by the application can significantly enhance the surface topological structure and greatly enhance the bonding strength of the fluorine-containing coating.

[0046] Polymer coatings have a wide range of applications in numerous fields, where products often face various environmental challenges (e.g., high temperature, high pressure, fluid scouring, etc.). Therefore, the firmness of the coating is directly related to its performance and service life. The crosshatch test method can intuitively evaluate the adhesion between the coating and the substrate through a series of strict steps, thereby ensuring that the quality of the coating meets the requirements. In the present invention, the polymer coating has a coating firmness of 4B or higher, as determined by the crosshatch test method. Furthermore, the polymer coating has a coating firmness of 5B. On a fluid-scoured or temperature-varying metal surface, the former will peel off the coating due to the shear force of fluid scouring, and the latter will peel off the coating due to the large difference in the thermal expansion coefficient between the coating and the metal. Especially for low-surface-energy fluorine-containing coatings (such as PTFE), the coating firmness of a conventional untreated metal surface is only 0B, which is extremely dangerous when it is applied to the medical field, because the peeling of the coating will cause the bare pipe surface to be more easily attached and proliferated by bacteria and microorganisms, thereby increasing the risk of infection and possibly causing uneven pipe surfaces, increasing friction and irritation, and causing serious damage to the cavity. The coating firmness of the surface treated by the secondary structure in the present application can reach 4B or higher, significantly improving the adhesion of the coating on various metal substrate surfaces.

[0047] Furthermore, if the adhesion of a polytetrafluoroethylene (PTFE) coating is only 3B, it may cause a series of performance and safety problems. Such a coating with low adhesion may exhibit early peeling in actual application, unable to resist mechanical impact in daily use, leading to a rapid decline in its protective performance. In addition, the chemical stability and environmental adaptability of the coating may also be insufficient, unable to maintain performance in harsh chemical environments or variable temperature and humidity conditions. These problems not only increase the maintenance cost and operation risk of the equipment, but also may affect the reliability and expected life of the entire equipment due to the early failure of the coating. In safety-sensitive applications, peeling of the coating may even cause equipment failure, increasing safety risks. At the same time, if the product cannot meet industry standards or regulatory requirements, it may face legal liability or regulatory review, thereby damaging the brand reputation and consumer trust of the manufacturer. Therefore, ensuring that the PTFE coating meets higher adhesion standards is crucial for improving the durability, reliability, and market competitiveness of the product.

[0048] The 4B level of adhesion ensures the adaptability of the coating under different environmental conditions, including extreme temperature and humidity changes, and the coating can maintain its performance without being damaged. This environmental adaptability is particularly important for equipment operating in variable environments, as it reduces performance degradation due to environmental factors. At the same time, the high adhesion of the coating also improves the safety of the equipment, reducing potential safety risks caused by coating failure. Finally, the high adhesion of the PTFE coating also improves the reliability of the product, enhancing consumer confidence in the performance of the product, thereby establishing a strong competitive advantage in the market.

[0049] Further, the metal substrate with polymer coating according to the present application is a medical device.

[0050] Further, the metal substrate with polymer coating according to the present application is a vehicle. Preferably a ship, a vehicle, an aircraft.

[0051] The present application also provides a method for preparing the aforementioned metal substrate with polymer coating, comprising the following steps: 1) providing a metal substrate; 2) first polishing the metal substrate with polishing material having a first grit to form a primary structure; 3) second polishing the metal substrate with polishing material having a second grit to form a secondary structure; 4) coating the metal substrate polished with the secondary structure with a polymer coating;

[0052] Further, the second grit is more than ten times the first grit.

[0053] The scheme of the present application is different from the traditional polishing of metal substrates. The difference lies in that the polishing of metal substrates is usually to improve the surface smoothness and brightness. The initial polishing usually uses coarse sandpaper (80-120 grit) to remove the oxidation layer, welding marks or other larger defects on the metal surface. Then, the sandpaper with slightly larger grit is replaced for intermediate polishing (240-400 grit), and finally, the sandpaper with larger grit is replaced for fine polishing (600 grit or more) to achieve a smooth and bright surface. However, the polishing method provided by the present application only needs to use two different specifications of polishing materials, and after two polishing, the secondary rough structure of the present application is formed.

[0054] In order to achieve the secondary rough structure according to the present application, the second grit needs to be significantly higher than the first grit. The inventors found that the second grit needs to be at least ten times higher than the first grit to achieve the micro-nano surface structure of the present application.

[0055] Further, the first polishing of the present application refers to the polishing with the first grit of sandpaper, not the number of polishing times. The first polishing can be adjusted according to the different substrate materials, for example, 1-10 times; or 10-20 times; or 20-40 times. Similarly, the second polishing of the present application refers to the polishing with the second grit of sandpaper, not the number of polishing times. The second polishing can be adjusted according to the different substrate materials, for example, 1-10 times; or 10-20 times; or 20-40 times.

[0056] Further, the first grit of the present application is at least 40 and the second grit is not more than 2000.

[0057] Specifically, the first grit is at least 40, and less than 40 is difficult to form an effective primary structure on the metal substrate. The second grit is not more than 2000, otherwise the secondary structure of the surface structure is too small, or it is difficult to build an effective secondary structure on the primary structure, which is difficult to produce effective adhesion to the subsequent coating.

[0058] In some embodiments, the first grit can be 40, 50, 60, 70, 80, 90, 100, 110, 120. In some embodiments, the second grit can be 600, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000. In practical applications, the appropriate first grit and second grit can be selected according to the characteristics of the specific metal substrate.

[0059] Further, in the present application, after the first polishing, the substrate can be cleaned to remove debris, particles and other debris generated during polishing, reducing the impact of the second polishing.

[0060] Further, the polishing direction of the present application is preferably consistent, which can reduce the debris and particles generated during polishing from falling into the structure ditch. Further, the first polishing direction is preferably consistent with the second polishing direction, which is more conducive to building a secondary structure on the primary structure formed without significantly damaging the original primary structure.

[0061] Further, in the present application, the metal substrate can be any metal material that can be polished, including but not limited to stainless steel, magnesium alloy, metal aluminum, titanium alloy, nickel-based alloy, cobalt-chromium alloy and precious metal alloy.

[0062] Further, in the present application, the polymer coating is a resin coating material, including but not limited to epoxy resin, fluorine-containing resin, polyurethane resin, acrylic resin, polyester resin, silicone resin. Further, the fluorine-containing resin is preferred.

[0063] Further, in the present application, the polishing material is a material with a certain abrasive particle size, including one or more of sandpaper, sand cloth, sand belt, and sand wheel.

[0064] Embodiment section

[0065] With reference to the above implementation, in order to make the technical scheme of the present application more specific, clear, and easy to understand, the technical scheme of the present application will be exemplified. However, it should be noted that the following examples are used to illustrate the present application, and those skilled in the art can understand that the examples are only exemplary and are not exhaustive.

[0066] Examples 1-12: Constructing secondary structure on the surface of a stainless steel substrate to improve the firmness of a polytetrafluoroethylene coating

[0067] The specific steps are as follows: using the first grit sandpaper as described in Table 1 to polish the stainless steel substrate, then further polishing the stainless steel substrate to construct a secondary structure using the second grit sandpaper as shown in the table, and finally coating a polytetrafluoroethylene coating on the surface of the treated stainless steel substrate and curing. The firmness of the polytetrafluoroethylene coating on the surface of the stainless steel substrate is characterized by the crosshatch test. The specific test data are shown in Table 1.

[0068] Comparative Examples 1-11: Polishing the surface of a stainless steel substrate according to Table 1

[0069] The specific steps are as follows: using the first grit sandpaper as described in Table 1 to polish the stainless steel substrate, then directly coating a polytetrafluoroethylene coating on the surface of the treated stainless steel substrate and curing; or using the first grit sandpaper and the second grit sandpaper as described in Table 1 to polish the stainless steel substrate, then coating a polytetrafluoroethylene coating on the surface of the treated stainless steel substrate and curing. The firmness of the polytetrafluoroethylene coating on the surface of the stainless steel substrate is characterized by the crosshatch test. The specific test data are shown in Table 1.

[0070] Table 1

[0071]

[0072] Examples 13-24: Constructing secondary structure on the surface of a nickel-titanium alloy substrate to improve the firmness of a polytetrafluoroethylene coating

[0073] The specific steps are as follows: using the first grit sandpaper as described in Table 2 to polish the nickel-titanium alloy substrate, then further polishing the nickel-titanium alloy substrate to construct a secondary structure using the second grit sandpaper as shown in the table, and finally coating a polytetrafluoroethylene coating on the surface of the treated nickel-titanium alloy substrate and curing. The firmness of the polytetrafluoroethylene coating on the surface of the nickel-titanium alloy substrate is characterized by the crosshatch test. The specific test data are shown in Table 2.

[0074] Comparative Examples 12-19: Polishing the surface of a nickel-titanium alloy substrate according to Table 2

[0075] The nickel-titanium alloy substrate was polished using the first grit sandpaper as described in Table 2, followed by coating a polytetrafluoroethylene coating directly on the surface of the treated nickel-titanium alloy substrate; or the nickel-titanium alloy substrate was polished using the first grit sandpaper and the second grit sandpaper as described in Table 2, followed by coating a polytetrafluoroethylene coating on the surface of the treated nickel-titanium alloy substrate and curing. The adhesion of the polytetrafluoroethylene coating on the surface of the nickel-titanium alloy substrate was characterized by the crosshatch test. The specific test data are shown in Table 2.

[0076] Table 2

[0077]

[0078] Examples 25-36: Constructing secondary structure on the surface of the metal aluminum substrate to improve the adhesion of the polytetrafluoroethylene coating

[0079] The specific steps were as follows: the metal aluminum substrate was polished using the first grit sandpaper as described in Table 3, followed by further polishing the metal aluminum substrate using the second grit sandpaper as shown in Table 3 to construct the secondary structure, and finally coating a polytetrafluoroethylene coating on the surface of the treated metal aluminum substrate and curing. The adhesion of the polytetrafluoroethylene coating on the surface of the metal aluminum substrate was characterized by the crosshatch test. The specific test data are shown in Table 3.

[0080] Comparative Examples 20-27: Constructing only primary structure on the surface of the metal aluminum substrate

[0081] The metal aluminum substrate was polished using the first grit sandpaper as described in Table 3, followed by coating a polytetrafluoroethylene coating directly on the surface of the treated metal aluminum substrate and curing. The adhesion of the polytetrafluoroethylene coating on the surface of the metal aluminum substrate was characterized by the crosshatch test. The specific test data are shown in Table 3.

[0082] Table 3

[0083]

[0084] Comparative Examples 28-30: Simulated polishing treatment on the surface of the substrate

[0085] The specific steps were as follows: first, 80 grit sandpaper was selected, and uniform force was applied to polish the surface of the metal substrate to remove the surface oxide layer, burrs, and larger unevenness. Then, 400 grit sandpaper was used to continue polishing uniformly; finally, sandpaper with a larger mesh (800 mesh) was replaced to polish uniformly again. After each step of polishing was completed, the surface was cleaned with a cleaning solution to remove the polishing debris. Finally, a polytetrafluoroethylene coating was coated on the surface of the treated metal substrate and cured. The adhesion of the polytetrafluoroethylene coating on the surface of the substrate was characterized by the crosshatch test, and the test results are shown in Table 4.

[0086] Table 4

[0087]

[0088] Examples 37-40: Constructing secondary structures on stainless steel substrates to improve the adhesion of different polymer coatings

[0089] The specific steps are as follows: First, sand the stainless steel substrate using sandpaper of the first grit as shown in Table 5. Then, further sand the stainless steel substrate using sandpaper of the second grit as shown in Table 5 to construct the secondary structure. Finally, coat the treated stainless steel substrate with a corresponding polymer coating and allow it to cure. The adhesion of the polymer coating on the stainless steel substrate surface is characterized by a cross-cut adhesion test. Specific test data are shown in Table 5.

[0090] Table 5

[0091]

[0092] The adhesion of polymer coatings on metal substrates was characterized using a cross-cut adhesion test (Tables 1-5). The results showed that polymer coatings on metal substrates with secondary structures achieved an adhesion rating of 5B in the cross-cut adhesion test. Furthermore, the method of utilizing secondary structures to improve the adhesion of polymer coatings demonstrated good effectiveness on a variety of different substrate surfaces.

[0093] Scanning electron microscope test

[0094] The surface morphology of untreated stainless steel substrates (Comparative Example 1), stainless steel substrates with primary structures (Comparative Example 4), and stainless steel substrates with secondary structures (Example 10) were analyzed using scanning electron microscopy at different magnifications. Figure 1 Experimental results show that the surface of the untreated metal substrate tends to be smooth and flat; the surface of the metal substrate with the primary structure exhibits a certain degree of roughness; and the microstructure of the metal substrate with the secondary structure shows that a rich topological structure is generated on the basis of the primary structure. The secondary structure on the surface of the metal substrate can effectively increase the surface area for bonding between the metal substrate and the polytetrafluoroethylene coating, thereby providing good adhesion.

Claims

1. A metal substrate with a polymer coating, comprising a metal substrate layer and a polymer coating covering the metal substrate layer, characterized in that, The metal substrate layer includes a micro / nano structure surface layer comprising a primary structure of micron-sized protrusions and a secondary structure of nano-sized protrusions distributed on the primary structure of the micron-sized protrusions. The micro / nano structure surface layer is covered by the polymer coating. Both the primary structure of the micron-sized protrusions and the secondary structure of the nano-sized protrusions are formed by physical polishing of the metal substrate itself, and their structural composition is consistent with that of the substrate. The polymer coating has a coating adhesion of 4B or higher, as determined by the cross-cut adhesion test. The primary structure of the micron-sized protrusions is formed by a first abrasive material with a grit of ≥40 mesh, and the secondary structure of the nano-sized protrusions is formed by a second abrasive material with a grit of ≤2000 mesh and more than 10 times that of the first abrasive material, and the two abrasive directions are consistent.

2. The metal substrate according to claim 1, characterized in that, The metals include stainless steel, magnesium alloys, aluminum, titanium alloys, nickel-based alloys, cobalt-chromium alloys, and precious metal alloys.

3. The metal substrate according to claim 1, characterized in that, The polymer coating is a resin coating, selected from one or more of epoxy resin, fluorinated resin, polyurethane resin, acrylic resin, polyester resin, and silicone resin.

4. The metal substrate according to claim 3, characterized in that, The polymer coating is a fluorinated resin.

5. A medical device having a metal substrate as described in any one of claims 1-4.

6. A vehicle having a metal substrate as described in any one of claims 1-4.

7. The means of transport according to claim 6, characterized in that, The means of transportation is selected from ships, vehicles, and aircraft.

8. A method for manufacturing a metal substrate with a polymer coating as described in any one of claims 1-4, comprising: Provide a metal substrate; The metal substrate is first polished with an abrasive material having a first abrasive grain to form a primary structure; The metal substrate is abraded a second time with a second abrasive material to form a secondary structure; A polymer coating is applied to the metal substrate with the secondary structure polished out. The second sand size is more than ten times that of the first sand size; The first sand mesh number must be at least 40 and the second sand mesh number must not exceed 2000; The directions of the first grinding with a first-grit abrasive material and the second grinding with a second-grit abrasive material are consistent.

9. The method for fabricating a metal substrate with a polymer coating according to claim 8, characterized in that, The metals include stainless steel, magnesium alloys, aluminum, titanium alloys, nickel-based alloys, cobalt-chromium alloys, and precious metal alloys.

10. The method for fabricating a metal substrate with a polymer coating according to claim 8, characterized in that, The polymer coating is a resin coating, selected from one or more of epoxy resin, fluorinated resin, polyurethane resin, acrylic resin, polyester resin, and silicone resin.

11. The method for fabricating a metal substrate with a polymer coating according to claim 8, characterized in that, The polishing material is a material with a certain abrasive particle size, including one or more of sandpaper, abrasive cloth, abrasive belt, and abrasive wheel.

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