A high-wear-resistant stainless steel-based composite coating, preparation method and application thereof on cabinet door panels

Abstract

The present invention relates to the field of coating materials, and provides a high-wear-resistant stainless steel-based composite coating, which is composed of dumbbell-shaped silver-doped silicon carbide, sea urchin-shaped titanium dioxide, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, etc. Silver-doped silicon carbide is prepared by sol-gel, high-temperature carbonization and pickling, and titanium dioxide filler is obtained by hydrothermal synthesis and calcination. It is deposited by supersonic flame spraying, and the density and bonding strength are enhanced by laser remelting. Finally, the wear resistance, anti-pollution and antibacterial properties are improved by vacuum annealing, mechanical polishing and hydrophobic coating modification. The present invention adopts dumbbell-shaped silver-doped silicon carbide and sea urchin-shaped titanium dioxide design to achieve high wear resistance, antibacterial and high bonding strength coating performance, solve the wear resistance and antibacterial problems, and is suitable for cabinet door panels and other fields.

Description

Technical Field

[0001] The present invention relates to the field of coating materials, and in particular to a high-wear-resistant stainless steel-based composite coating, a preparation method thereof, and application thereof on cabinet door panels. Background Art

[0002] In modern home and industrial applications, stainless steel, due to its excellent mechanical properties, corrosion resistance, and aesthetic appeal, is widely used in cabinet doors, medical equipment, food processing countertops, and high-end electronic product housings. However, due to frequent use and complex environmental conditions, traditional stainless steel surfaces are susceptible to wear, scratching, and contamination. Microbial growth, particularly in kitchens and medical environments, directly impacts safety and hygiene standards. Therefore, the development of composite coatings with both high wear resistance and antimicrobial properties is crucial for extending the service life of stainless steel products, reducing maintenance costs, and improving safety and hygiene standards. In terms of material performance requirements, an ideal composite coating should possess high hardness and excellent wear resistance to withstand long-term mechanical friction, while also possessing strong adhesion and a dense structure to ensure stability in complex environments. Furthermore, the antimicrobial properties of the coating surface must effectively inhibit the growth of microorganisms such as bacteria and fungi, and maintain long-lasting antimicrobial performance in environments with humidity, heat, oil, and contamination. In practical applications, the development of coatings with both wear resistance and antimicrobial properties not only improves product durability and safety but also promotes technological advancements in the industry and promotes the widespread application of high-performance functional coatings.

[0003] Although the current stainless steel surface modification technology has made certain progress, there are still many challenges in the coordinated optimization of wear resistance and antibacterial properties. For example, publication number CN106835120A discloses a self-lubricating, wear-resistant and corrosion-resistant coating of austenitic stainless steel, but the coating does not have an antibacterial design. On the other hand, publication number CN118291973A discloses a copper-containing antibacterial martensitic stainless steel coating and its preparation method, which shows a certain effect in inhibiting bacterial growth, but there are certain limitations in wear resistance. Therefore, while the existing technology improves the wear resistance of stainless steel coatings, it often cannot take into account long-term antibacterial properties, and in the design of enhancing antibacterial ability, the mechanical durability of the coating may be sacrificed. These problems are mainly due to insufficient filler optimization, microstructure design defects and limitations of the preparation process. Therefore, the development of a stainless steel-based composite coating that has high wear resistance, high bonding strength and long-term antibacterial properties is still a key issue that needs to be urgently addressed in the current material research and application fields. Summary of the Invention

[0004] (1) Technical problems solved

[0005] The purpose of the present invention is to provide a highly wear-resistant stainless steel-based composite coating, a preparation method and its application on cabinet door panels, so as to solve the problem that the current coating has insufficient wear resistance and antibacterial properties.

[0006] (2) Technical solution

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A high-wear-resistant stainless steel-based composite coating comprises the following raw materials in parts by weight: 10.0-20.0 parts of dumbbell-shaped silver-doped silicon carbide filler, 5.0-15.0 parts of sea urchin-shaped titanium dioxide filler, 25.0-30.0 parts of 304 stainless steel powder, 20.0-30.0 parts of NiCrBSi nickel-based self-soluble alloy powder, 0.5-3.0 parts of boron oxide filler, 5.0-15.0 parts of nano-alumina filler, 3.0-10.0 parts of nano-zirconia filler, 2.0-5.0 parts of boron nitride filler, and 0.5-3.0 parts of rare earth oxide;

[0009] The dumbbell-shaped silver-doped silicon carbide filler is prepared by a sol-gel method combined with high-temperature carbonization and acid washing purification processes;

[0010] The sea urchin-shaped titanium dioxide is prepared by a hydrothermal synthesis method combined with high-temperature calcination.

[0011] Furthermore, the preparation method of the dumbbell-shaped silver-doped silicon carbide filler is as follows: 10.0-50.0 parts of glucose and 10.0 parts of tetraethoxysilane are mixed in a mass ratio of (1-5):1, the mixed raw materials are placed in a stirring tank, the stirring rate is 500-800 rpm, the stirring time is 30-60 min, until a uniform solution is formed, and then 2.0-5.0 parts of 0.01 mol / L hydrochloric acid are added to the solution to adjust the pH to 3.0-5. .0, maintain the stirring rate at 300-500 rpm for 20-40 minutes to form a uniform gel, heat the obtained gel solution to 50-80 ° C, increase the temperature at a heating rate of 2-5 ° C / min, and keep it warm for 12-24 hours. Keep stirring at a constant temperature of 50-80 ° C until the solvent evaporates to form a solid precursor. Place the precursor in a vacuum drying oven and dry it at a temperature of 80-120 ° C for 6-12 hours to obtain a carbon-silicon composite precursor powder. The powder was redispersed in 100-120 parts of ethanol and stirred at a stirring rate of 500-800 rpm for 20-30 minutes to form a suspension. Subsequently, 2.0-4.5 parts of 0.05 mol / L silver nitrate solution were slowly added and stirred at a constant temperature of 25-40°C for 30-45 minutes. The mixture was then transferred to a vacuum drying oven and dried at 60-80°C to constant weight. The solid powder was collected and placed in a tube furnace and heated at a heating rate of 5-10°C / min under an argon atmosphere. The method comprises the following steps: heating the product to 1200-1600° C. at a high rate, keeping the temperature for 120-240 minutes, and naturally cooling the product to room temperature. The product is then immersed in a 1 mol / L hydrochloric acid solution for 30-60 minutes for pickling. The product is then separated by a centrifuge at 5000-8000 rpm for 5-10 minutes. The precipitate is washed with deionized water for 3-5 times, each time using 3-5 times the volume of the precipitate. The product is finally dried in a vacuum drying oven at 80-120° C. for 6-12 hours to obtain a dumbbell-shaped silver-doped silicon carbide filler.

[0012] Furthermore, the dumbbell-shaped silver-doped silicon carbide filler has an average length of 200 to 600 nm, an average diameter of the neck of 65 to 200 nm, and an average diameter of the end of 90 to 400 nm.

[0013] Furthermore, the silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler is 1.5 to 3.0 at.%.

[0014] The present invention adopts the design of dumbbell-shaped silver-doped silicon carbide filler mainly to enhance the wear resistance and antibacterial properties of the coating. The structure and composition of the filler work synergistically to improve the mechanical properties of the coating while giving it excellent antibacterial properties. The dumbbell-shaped silver-doped silicon carbide filler prepared by the sol-gel method combined with high-temperature carbonization and acid washing purification process has a unique nanostructure with an average length range of 200 to 600 nm. The gradient size design of the neck and end helps to improve the uniform dispersion and interfacial bonding of the filler in the coating matrix, thereby enhancing the wear resistance and mechanical stability of the coating. In addition, the silicon carbide body of the filler provides high hardness and excellent wear resistance, while the silver doping amount is controlled at 1.5 to 3.0 at.%, ensuring that the antibacterial activity of the filler can effectively inhibit the growth of microorganisms while maintaining its mechanical strength. During its preparation process, by adjusting the carbonization temperature (1200 to 1600 ° C) and the acid washing purification step, impurities are effectively removed, the purity and surface activity of the filler are improved, and its dispersibility in the coating is further optimized. The silver-doped silicon carbide nanostructure not only increases the bonding area with the substrate but also promotes uniform distribution of silver, enabling long-term and stable antibacterial effects. The synergistic effect of this filler in the coating ensures that the final coating maintains good wear resistance under high-load friction environments, while also exhibiting excellent antibacterial properties in humid and complex environments, thus meeting the demand for high-performance protective coatings in high-end manufacturing, medical equipment, and food processing.

[0015] Furthermore, the preparation method of the sea urchin-shaped titanium dioxide filler is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol are used as raw materials, and are mixed in a volume ratio of (0.3-0.5 mL): (20-40 mL): (30-50 mL), the mixed solution is placed in a stirring container and stirred at a rate of 300-600 rpm for 10-30 minutes, and then transferred to an ultrasonic device and treated at a frequency of 40-60 kHz for 3-10 minutes to obtain a uniform dispersion system, and the dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, heated to 160-200°C at 2-5°C / min and kept warm for 8-16 hours. After the reaction is completed, the mixture is cooled to 25-30°C at a rate of 2-5°C / min, 0.1-0.5M hydrochloric acid is then added dropwise to the coolant to adjust the pH to 6-7, and the mixture is centrifuged at 5000-10000 rpm for 5-10 min to obtain a precipitate. The precipitate is washed 3-5 times with a 0.1 mol / L hydrochloric acid / deionized water mixture with a volume ratio of 1:1, each time with an amount of 30-50 ml. The precipitate is dried in a vacuum drying oven at 50-80°C for 8-16 hours, and then transferred to a tubular furnace and heated to 500-600°C at a rate of 2-10°C / min and calcined for 60-120 minutes. Finally, the sea urchin-shaped titanium dioxide filler is obtained after grinding.

[0016] Furthermore, the average diameter of the sea urchin-shaped titanium dioxide filler is 1.5 to 4.5 μm, and the thorn-like branches on its surface are composed of nano-scale titanium dioxide whiskers of 100 to 200 nm.

[0017] The present invention adopts the design of sea urchin-shaped titanium dioxide filler mainly for enhancing the wear resistance and antibacterial properties of the coating. The special morphology and microstructure of the filler give the coating excellent mechanical properties and long-term antibacterial ability. The sea urchin-shaped titanium dioxide filler prepared by hydrothermal reaction combined with high-temperature calcination using tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol as raw materials forms a micromorphology with a core-shell structure, with an average diameter range of 1.5 to 4.5 μm, and the surface thorn-like branches are composed of nano-scale titanium dioxide whiskers. This unique three-dimensional layered structure not only provides a larger specific surface area, which helps to improve the uniform dispersion of the filler in the matrix, but also can form a reinforcing phase inside the coating, improving the overall wear resistance. In practical applications, the filler can form a microscopic intercalation effect inside the coating through its thorn-like branches, enhance the bonding force between the coating and the substrate, effectively resist the effects of external mechanical stress, and avoid the interface shedding problem that may be caused by traditional spherical fillers. In addition, titanium dioxide itself has excellent photocatalytic and antibacterial properties. Its nanoscale whiskers can continuously release reactive oxygen species under light or specific conditions, thereby destroying microbial cell membranes and achieving long-lasting antibacterial function. By optimizing the hydrothermal synthesis and calcination process, the filler is ensured to maintain a high specific surface area and nanostructure while possessing good crystallinity and chemical stability, enabling it to exert long-term reinforcing and antibacterial effects in the coating. This not only improves the coating's wear resistance, but also significantly enhances its antibacterial durability in complex environments, thus meeting the demand for high-performance protective coatings in high-end manufacturing, medical equipment, food processing and other fields.

[0018] Furthermore, the rare earth oxide is yttrium oxide or lanthanum oxide.

[0019] The present invention also discloses a method for preparing a highly wear-resistant stainless steel-based composite coating, comprising the following steps:

[0020] S1. Substrate pretreatment: Cold-rolled low-carbon steel plate was used as the substrate material and mechanical sandblasting was performed in sequence. 80-120 mesh brown corundum sand was used for sandblasting, the sandblasting pressure was 0.4-0.6 MPa, and the surface roughness Ra = 3.2-6.3 μm). Then, alkaline degreasing was performed. The specific process was to immerse the treated base material in an alkaline degreasing agent at 60-80°C and pH 10-12 for ultrasonic cleaning for 5-10 minutes, and then treat it in a 10wt.% dilute hydrochloric acid solution at room temperature for 30-60 seconds. After washing with water and drying, the pretreatment was completed.

[0021] S2. Raw material mixing and powder preparation: dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler and rare earth oxide were added to a three-dimensional mixer and uniformly mixed at 15-25 rpm under argon protection for 60-90 minutes. The mixture was then sieved three times through a 150-200 mesh sieve to obtain a composite spray powder with uniform composition.

[0022] S3: Supersonic flame spray deposition: Use supersonic flame spray equipment, set the kerosene flow rate to 22-26L / h, and the oxygen flow rate to 750-850m 3 / h, powder feeding rate 35 ~ 45g / min, deposition on the substrate surface preheated to 160 ~ 220 ℃ at a spray distance of 280 ~ 320mm, divided into 3 to 5 spraying passes, single layer thickness controlled at 30 ~ 50μm, interlayer cooling temperature ≤ 80 ℃ to avoid thermal stress accumulation;

[0023] S4. Laser Remelting and Surface Densification: The coating was remelted using a fiber laser with a spot diameter of 2–4 mm, a scan rate of 10–15 mm / s, and an overlap ratio of 30–40%. Argon gas curtain protection was used with a gas flow rate of 15–25 L / min and a controlled cooling rate of 50–80°C / s.

[0024] S5: Precision post-processing and surface finishing: Place the coating in a vacuum annealing furnace and keep it at 180-240℃ for 2-4 hours to eliminate internal stress, then use 800-1500 mesh sand belt for mechanical polishing to reduce the surface roughness to Ra≤0.8μm, and finally spray heptafluorodecyltrimethoxysilane with a thickness of 1.0-3.0μm, and cure it at 120-150℃ for 20-30min to form an anti-fingerprint and pollution-resistant inert surface.

[0025] The invention also discloses application of a high-wear-resistant stainless steel-based composite coating on a cabinet door panel.

[0026] The present invention aims to prepare a highly wear-resistant stainless steel-based composite coating, which improves the wear resistance, antibacterial properties, bonding strength and environmental adaptability of the coating through the synergistic effect of various components. The dumbbell-shaped silver-doped silicon carbide filler provides high hardness and wear resistance, while the silver doping gives the coating long-lasting antibacterial properties; the three-dimensional thorn-like structure of the sea urchin-shaped titanium dioxide filler improves the filler dispersion, enhances the mechanical strength of the coating, and further optimizes the antibacterial properties through the photocatalytic effect; 304 stainless steel powder is used as the matrix material to ensure the structural stability and matching of the coating; NiCrBSi nickel-based self-soluble alloy powder provides excellent bonding and corrosion resistance through supersonic flame spraying, enhancing overall durability. Boron oxide filler optimizes the wettability of the coating and promotes melt bonding. Nano-alumina and nano-zirconia fillers synergistically improve hardness, wear resistance and thermal stability. Boron nitride filler reduces the friction coefficient and improves lubricity. Rare earth oxide strengthens the density and high-temperature stability of the coating. Through sandblasting, uniform powder mixing, HVOF spraying, laser remelting, and precision post-processing, the coating achieves excellent adhesion and smoothness. A hydrophobic coating enhances contamination resistance. Ultimately, the composite coating demonstrates exceptional wear resistance, antibacterial properties, and environmental tolerance in applications such as cabinet door panels, meeting the demands of high-end manufacturing and long-term use.

[0027] (3) Beneficial technical effects

[0028] 1. This invention achieves a synergistic enhancement of wear resistance and antibacterial properties through structural optimization of dumbbell-shaped silver-doped silicon carbide fillers. Compared with traditional fillers, it improves dispersibility and interfacial bonding strength, avoiding flaking problems. The silicon carbide body provides high hardness, silver doping ensures long-term antibacterial effects, and the nanostructure optimizes the uniformity of the filler in the matrix, enhancing mechanical stability. Purity and surface activity are controlled through sol-gel methods and high-temperature carbonization processes, ensuring that the coating still has excellent wear resistance under high-load friction environments while maintaining antibacterial effects in humid environments. It is suitable for high-end manufacturing, medical equipment, and food processing.

[0029] 2. The present invention achieves a synergistic enhancement of the wear resistance and antibacterial properties of the coating by optimizing the microstructure of the sea urchin-shaped titanium dioxide filler. Compared with traditional spherical fillers, the uniform dispersion and interfacial bonding strength of the filler in the matrix are improved, thus avoiding the problem of shedding. The intercalation of the thorn-like branches enhances the overall mechanical properties, and the photocatalytic effect gives the coating long-lasting antibacterial ability. The optimized hydrothermal synthesis and calcination process ensures high crystallinity and chemical stability of the filler, enabling the coating to exhibit excellent durability and antibacterial persistence in high-end manufacturing, medical equipment, and food processing, meeting stringent usage requirements.

[0030] 3. The present invention significantly improves the wear resistance, antibacterial properties and durability of stainless steel-based composite coatings through the coordinated optimization of multifunctional fillers, breaking through the bottleneck of existing technologies in balancing wear resistance and antibacterial properties. Dumbbell-shaped silver-doped silicon carbide and sea urchin-shaped titanium dioxide synergistically enhance mechanical strength and antibacterial ability, NiCrBSi nickel-based alloy and 304 stainless steel powder ensure the structural stability of the coating, nano-alumina, zirconium oxide and boron nitride jointly enhance the wear resistance and lubrication properties, and rare earth oxides optimize density and high-temperature stability. After supersonic flame spraying and laser remelting treatment, the coating has strong bonding strength and a smooth surface, making it suitable for high-wear-resistant and antibacterial scenarios such as cabinet door panels, extending service life and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a morphology picture of the dumbbell-shaped silver-doped silicon carbide filler prepared in Example 1 of the present invention.

[0032] Figure 2 This is a phase analysis diagram of the dumbbell-shaped silver-doped silicon carbide filler prepared in Example 1 of the present invention.

[0033] Figure 3 This is a morphology picture of the sea urchin-shaped titanium dioxide filler prepared in Example 1 of the present invention.

[0034] Figure 4 This is a phase analysis diagram of the sea urchin-shaped titanium dioxide filler prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0036] Example 1

[0037] A highly wear-resistant stainless steel-based composite coating comprises the following raw materials in parts by weight: 10.0 parts of dumbbell-shaped silver-doped silicon carbide filler, 5.0 parts of sea urchin-shaped titanium dioxide filler, 25.0 parts of 304 stainless steel powder, 20.0 parts of NiCrBSi nickel-based self-soluble alloy powder, 0.5 parts of boron oxide filler, 5.0 parts of nano-alumina filler, 3.0 parts of nano-zirconia filler, 2.0 parts of boron nitride filler, and 0.5 parts of rare earth oxide;

[0038] Dumbbell-shaped silver-doped silicon carbide filler was prepared by a sol-gel method combined with high-temperature carbonization and acid washing purification process; sea urchin-shaped titanium dioxide was prepared by a hydrothermal synthesis method combined with high-temperature calcination.

[0039] The preparation method of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is as follows: 10.0 parts of glucose and 10.0 parts of tetraethoxysilane are used as raw materials and mixed in a mass ratio of 1:1, the mixed raw materials are placed in a stirring kettle, the stirring rate is 500 rpm, and the stirring time is 30 minutes until a uniform solution is formed, then 2.0 parts of 0.01 mol / L hydrochloric acid are added to the solution, the pH is adjusted to 3.0, and the stirring rate is maintained at 300 rpm for 20 minutes to form a uniform gel, the obtained gel solution is heated to 50°C, the temperature is increased at a heating rate of 2°C / min, the holding time is 12 hours, and constant temperature stirring is maintained at 50°C until the solvent evaporates to form a solid precursor, the precursor is placed in a vacuum drying oven, and dried at a temperature of 80°C for 6 hours to obtain a carbon-silicon composite precursor powder, and the dry The dried powder was redispersed in 100 parts of ethanol and stirred at a stirring rate of 500 rpm for 20 minutes to form a suspension. Subsequently, 2.0 parts of 0.05 mol / L silver nitrate solution were slowly added and stirred at a constant temperature of 25°C for 30 minutes. The mixture was then transferred to a vacuum drying oven and dried at 60°C to constant weight. The solid powder was collected and placed in a tube furnace. It was heated to 1200°C at a heating rate of 5°C / min under an argon atmosphere and kept warm for 120 minutes. After naturally cooling to room temperature, the product was immersed in a 1 mol / L hydrochloric acid solution for 30 minutes for acid washing. The product was separated by a centrifuge at 5000 rpm for 5 minutes. The precipitate was washed with deionized water three times, each time with an amount of 3 times the volume of the precipitate. Finally, it was dried in a vacuum drying oven at 80°C for 6 hours to obtain a dumbbell-shaped silver-doped silicon carbide filler.

[0040] The dumbbell-shaped silver-doped silicon carbide filler of this embodiment has an average length of 200 nm, an average diameter of the neck of 65 nm, and an average diameter of the end of 90 nm.

[0041] The silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is 1.5 at.%.

[0042] The preparation method of the sea urchin-shaped titanium dioxide filler in this embodiment is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution, and ethylene glycol are mixed as raw materials in a volume ratio of 0.3:20:30, the mixture is placed in a stirring container and stirred at a rate of 300 rpm for 10 minutes, then transferred to an ultrasonic device and treated at a frequency of 40 kHz for 3 minutes to obtain a uniform dispersion system, the dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, the temperature is increased to 160° C. at a rate of 2° C. / min and kept at this temperature for 8 hours, after which the reaction is completed, the temperature is cooled to 25° C. at a rate of 2° C. / min, 0.1 M hydrochloric acid is then added dropwise to the coolant to adjust the pH to 6, the mixture is centrifuged at 5000 rpm for 5 minutes to obtain a precipitate, the precipitate is washed three times with a 0.1 mol / L hydrochloric acid / deionized water mixture at a volume ratio of 1:1, using 30 ml each time, the precipitate is dried in a vacuum drying oven at 50° C. for 8 hours, then transferred to a tube furnace and heated to 500° C. at a rate of 2° C. / min and calcined for 60 minutes, and finally ground to obtain the sea urchin-shaped titanium dioxide filler.

[0043] The average diameter of the sea urchin-shaped titanium dioxide filler in this embodiment is 1.5 μm, and the thorn-like branches on its surface are composed of 100 nm nano-scale titanium dioxide whiskers.

[0044] The rare earth oxide in this embodiment is yttrium oxide.

[0045] The method for preparing a highly wear-resistant stainless steel-based composite coating of this embodiment comprises the following steps:

[0046] S1. Substrate pretreatment: Cold-rolled low-carbon steel and aluminum alloy plates were used as substrates and mechanically sandblasted using 80-mesh brown corundum sand at a blasting pressure of 0.4 MPa and a surface roughness of Ra = 3.2 μm. Alkaline degreasing was then performed. The treated substrate was ultrasonically cleaned in an alkaline degreasing agent at 60°C and pH 10 for 5 min, followed by treatment in a 10 wt.% dilute hydrochloric acid solution at room temperature for 30 s. The substrate was then rinsed with water and dried to complete the pretreatment.

[0047] S2. Raw material mixing and powder preparation: dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler and rare earth oxide were put into a three-dimensional mixer and uniformly mixed at 15 rpm for 60 min under argon protection. Then, the mixture was sieved three times through a 150-mesh sieve to obtain a composite spray powder with uniform composition;

[0048] S3: Supersonic flame spray deposition: Use supersonic flame spray equipment, set the kerosene flow rate to 22L / h and the oxygen flow rate to 750m 3 / h, powder feeding rate 35g / min, deposition on the substrate surface preheated to 160℃ at a spray distance of 280mm, spraying in 3 passes, single layer thickness controlled to 30μm, interlayer cooling temperature ≤80℃ to avoid thermal stress accumulation;

[0049] S4. Laser Remelting and Surface Densification: The coating was remelted using a fiber laser with a spot diameter of 2 mm, a scan rate of 10 mm / s, and an overlap ratio of 30%. Argon gas curtain protection was used with a gas flow rate of 15 L / min and a controlled cooling rate of 50°C / s.

[0050] S5: Precision post-processing and surface finishing: The coating is placed in a vacuum annealing furnace and kept at 180°C for 2 hours to eliminate internal stress. It is then mechanically polished with an 800-grit sand belt to reduce the surface roughness to Ra ≤ 0.8μm. Finally, a coating of 17-fluorodecyltrimethoxysilane is sprayed on with a thickness of 1.0μm and cured at 120°C for 20 minutes to form an anti-fingerprint and pollution-resistant inert surface.

[0051] Figure 1 The morphological characteristics of the dumbbell-shaped silver-doped silicon carbide filler prepared in Example 1 of the present invention are shown, and the formation of the dumbbell-shaped structure is clearly demonstrated, proving the successful construction of the morphology. Figure 2 The crystal structure and phase composition of the filler were further verified through phase analysis, confirming the effectiveness of the phase in the preparation process. Figure 3 The morphological characteristics of sea urchin-like titanium dioxide fillers are demonstrated, and the thorn-like branches on the surface are evenly distributed, proving the successful realization of the sea urchin-like structure. Figure 4 Combined with phase analysis, the crystal structure of the sea urchin-shaped titanium dioxide filler was confirmed, further demonstrating the phase validity of the prepared filler. These analytical results collectively demonstrate that the preparation method employed in this invention can stably produce functional fillers with the target microstructure, providing a reliable material foundation for improving coating performance.

[0052] Example 2

[0053] A highly wear-resistant stainless steel-based composite coating comprises the following raw materials in parts by weight: 13 parts of dumbbell-shaped silver-doped silicon carbide filler, 8 parts of sea urchin-shaped titanium dioxide filler, 26.5 parts of 304 stainless steel powder, 23 parts of NiCrBSi nickel-based self-soluble alloy powder, 1.3 parts of boron oxide filler, 8 parts of nano-alumina filler, 5.1 parts of nano-zirconia filler, 2.9 parts of boron nitride filler, and 1.3 parts of rare earth oxide;

[0054] The preparation method of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is as follows: 22 parts of glucose and 10.0 parts of tetraethoxysilane are used as raw materials, and they are mixed in a mass ratio of 2.2:1. The mixed raw materials are placed in a stirring kettle, and the stirring rate is 590 rpm and the stirring time is 39 minutes until a uniform solution is formed. Subsequently, 2.9 parts of 0.01 mol / L hydrochloric acid are added to the solution, and the pH is adjusted to 3.6. The stirring rate is maintained at 360 rpm for 26 minutes to form a uniform gel. The obtained gel solution is heated to 59°C, and the temperature is increased at a heating rate of 2.9°C / min. The holding time is 15.6 hours. Constant temperature stirring is maintained at 59°C until the solvent evaporates to form a solid precursor. The precursor is placed in a vacuum drying oven and dried at a temperature of 92°C for 7.8 hours to obtain a carbon-silicon composite precursor powder. The dried powder The residue was redispersed in 106 parts of ethanol and stirred at a stirring rate of 590 rpm for 23 minutes to form a suspension. Subsequently, 2.8 parts of 0.05 mol / L silver nitrate solution were slowly added and stirred at a constant temperature of 29.5°C for 34.5 minutes. The mixture was then transferred to a vacuum drying oven and dried at 66°C to constant weight. The solid powder was collected and placed in a tube furnace. It was heated to 1320°C at a heating rate of 6.5°C / min under an argon atmosphere and kept warm for 156 minutes. After naturally cooling to room temperature, the product was immersed in a 1 mol / L hydrochloric acid solution for 39 minutes for acid washing. The product was separated by a centrifuge at 5900 rpm for 6.5 minutes. The precipitate was washed with deionized water 3.6 times, each time with an amount of 3.6 times the volume of the precipitate. Finally, it was dried in a vacuum drying oven at 92°C for 7.8 hours to obtain a dumbbell-shaped silver-doped silicon carbide filler.

[0055] The dumbbell-shaped silver-doped silicon carbide filler of this embodiment has an average length of 320 nm, an average diameter of the neck of 105 nm, and an average diameter of the end of 183 nm.

[0056] The silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is 1.95 at.%.

[0057] The preparation method of the sea urchin-shaped titanium dioxide filler in this embodiment is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol are mixed at a volume ratio of 0.36:26:36, the mixture is placed in a stirring container and stirred at a rate of 390 rpm for 16 minutes, and then transferred to an ultrasonic device and treated at a frequency of 46 kHz for 5.1 minutes to obtain a uniform dispersion system. The dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, heated to 172°C at a rate of 2.9°C / min and kept warm for 10.4 hours. After the reaction is completed, The mixture was cooled to 26.5°C at 2.9°C / min, and then 0.22M hydrochloric acid was added dropwise to the coolant to adjust the pH to 6.3. The mixture was centrifuged at 6500rpm for 6.5min to obtain a precipitate. The precipitate was washed 3.6 times with a 0.1mol / L hydrochloric acid / deionized water mixture with a volume ratio of 1:1, each time using 36ml. The precipitate was dried in a vacuum drying oven at 59°C for 10.4h, transferred to a tubular furnace, heated to 530°C at 4.4°C / min, and calcined for 78min. Finally, the sea urchin-shaped titanium dioxide filler was obtained after grinding.

[0058] The average diameter of the sea urchin-shaped titanium dioxide filler in this embodiment is 2.4 μm, and the thorn-like branches on its surface are composed of 130 nm nano-scale titanium dioxide whiskers.

[0059] The rare earth oxide in this embodiment is lanthanum oxide.

[0060] The method for preparing a highly wear-resistant stainless steel-based composite coating of this embodiment comprises the following steps:

[0061] S1. Substrate pretreatment: Cold-rolled low-carbon steel and aluminum alloy plates were used as substrates and mechanically sandblasted using 92-mesh brown corundum sand at a blasting pressure of 0.46 MPa and a surface roughness of Ra = 4.1 μm. Alkaline degreasing was then performed. The treated substrate was ultrasonically cleaned in an alkaline degreasing agent at 66°C and pH 10.6 for 6.5 min, followed by treatment in a 10 wt.% dilute hydrochloric acid solution at room temperature for 39 s. The substrate was then rinsed with water and dried to complete the pretreatment.

[0062] S2. Raw material mixing and powder preparation: Dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler and rare earth oxide were put into a three-dimensional mixer and uniformly mixed at 18 rpm for 69 minutes under argon protection. The mixture was then sieved three times through a 165-mesh sieve to obtain a composite spray powder with uniform composition.

[0063] S3: Supersonic flame spray deposition: Using supersonic flame spray equipment, set the kerosene flow rate to 23.2L / h and the oxygen flow rate to 780m 3 / h, powder feeding rate 38g / min, deposition on the substrate surface preheated to 178℃ at a spray distance of 292mm, spraying in 3.6 passes, single layer thickness controlled to 36μm, interlayer cooling temperature ≤80℃ to avoid thermal stress accumulation;

[0064] S4. Laser Remelting and Surface Densification: The coating was remelted using a fiber laser with a spot diameter of 2.6 mm, a scan rate of 11.5 mm / s, and an overlap ratio of 33%. Argon gas curtain protection was used with a gas flow rate of 18 L / min and a controlled cooling rate of 59°C / s.

[0065] S5: Precision post-processing and surface finishing: The coating is placed in a vacuum annealing furnace at 198°C for 2.6 hours to eliminate internal stress, and then mechanically polished with a 1010-grit sand belt to reduce the surface roughness to Ra ≤ 0.8μm. Finally, a coating of 17-fluorodecyltrimethoxysilane is sprayed with a thickness of 1.6μm and cured at 129°C for 23 minutes to form an anti-fingerprint and pollution-resistant inert surface.

[0066] Example 3

[0067] A highly wear-resistant stainless steel-based composite coating, comprising the following raw materials in parts by weight: 16 parts of dumbbell-shaped silver-doped silicon carbide filler, 11 parts of sea urchin-shaped titanium dioxide filler, 28 parts of 304 stainless steel powder, 26 parts of NiCrBSi nickel-based self-soluble alloy powder, 2.0 parts of boron oxide filler, 11 parts of nano-alumina filler, 7.2 parts of nano-zirconia filler, 3.8 parts of boron nitride filler, and 2.0 parts of rare earth oxide;

[0068] The preparation method of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is as follows: 34 parts of glucose and 10.0 parts of tetraethoxysilane are used as raw materials, and they are mixed in a mass ratio of 3.4:1. The mixed raw materials are placed in a stirring kettle with a stirring rate of 680 rpm and a stirring time of 48 minutes until a uniform solution is formed, and then 3.8 parts of 0.01 mol / L hydrochloric acid are added to the solution, the pH is adjusted to 4.2, and the stirring rate is maintained at 420 rpm for 32 minutes to form a uniform gel, and the obtained gel solution is heated to 68°C, and the temperature is increased at a heating rate of 3.8°C / min, and the holding time is 19.2 hours. The constant temperature is maintained at 68°C with stirring until the solvent evaporates to form a solid precursor, and the precursor is placed in a vacuum drying oven and dried at a temperature of 104°C for 9.6 hours to obtain a carbon-silicon composite precursor powder. The dried powder was redispersed in 112 parts of ethanol and stirred at a stirring rate of 680 rpm for 26 minutes to form a suspension. Subsequently, 3.5 parts of 0.05 mol / L silver nitrate solution were slowly added and stirred at a constant temperature of 34°C for 39 minutes. The mixture was then transferred to a vacuum drying oven and dried at 72°C to constant weight. The solid powder was collected and placed in a tube furnace. It was heated to 1440°C at a heating rate of 8°C / min under an argon atmosphere and kept warm for 192 minutes. After naturally cooling to room temperature, the product was immersed in a 1 mol / L hydrochloric acid solution for 48 minutes for acid washing. The product was separated by a centrifuge at 6800 rpm for 8 minutes. The precipitate was washed with deionized water 4.2 times, each time with an amount of 4.2 times the volume of the precipitate. Finally, it was dried in a vacuum drying oven at 104°C for 9.6 hours to obtain a dumbbell-shaped silver-doped silicon carbide filler.

[0069] The dumbbell-shaped silver-doped silicon carbide filler of this embodiment has an average length of 440 nm, an average diameter of the neck of 146 nm, and an average diameter of the end of 276 nm.

[0070] The silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is 2.4 at.%.

[0071] The preparation method of the sea urchin-shaped titanium dioxide filler in this embodiment is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol are mixed at a volume ratio of 0.42:32:42, the mixture is placed in a stirring container and stirred at a rate of 480 rpm for 22 minutes, and then transferred to an ultrasonic device and treated at a frequency of 52 kHz for 7.2 minutes to obtain a uniform dispersion system. The dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, heated to 184°C at a rate of 3.8°C / min and kept at this temperature for 12.8 hours, and the reaction is completed. The mixture was cooled to 28°C at a rate of 3.8°C / min, and 0.34M hydrochloric acid was added dropwise to the coolant to adjust the pH to 6.6. The mixture was centrifuged at 8000rpm for 8min to obtain a precipitate. The precipitate was washed 4.2 times with a 0.1mol / L hydrochloric acid / deionized water mixture with a volume ratio of 1:1, each time using 42ml. The precipitate was dried in a vacuum drying oven at 68°C for 12.8h, transferred to a tubular furnace, heated to 560°C at a rate of 6.8°C / min, and calcined for 96min. Finally, the sea urchin-shaped titanium dioxide filler was obtained after grinding.

[0072] The average diameter of the sea urchin-shaped titanium dioxide filler in this embodiment is 3.3 μm, and the thorn-like branches on its surface are composed of 160 nm nano-scale titanium dioxide whiskers.

[0073] The rare earth oxide in this embodiment is yttrium oxide.

[0074] The method for preparing a highly wear-resistant stainless steel-based composite coating of this embodiment comprises the following steps:

[0075] S1. Substrate pretreatment: Cold-rolled low-carbon steel and aluminum alloy plates were mechanically sandblasted using 104-mesh brown corundum sand at a pressure of 0.52 MPa and a surface roughness of Ra = 5.1 μm. Alkaline degreasing was then performed. The treated substrate was ultrasonically cleaned in an alkaline degreasing agent at 72°C and pH 11.2 for 8 min, followed by treatment in a 10 wt.% dilute hydrochloric acid solution at room temperature for 48 s. The substrate was then rinsed with water and dried to complete the pretreatment.

[0076] S2. Raw material mixing and powder preparation: dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler and rare earth oxide were put into a three-dimensional mixer and uniformly mixed at 21 rpm under argon protection for 78 minutes. The mixture was then sieved three times through a 180-mesh sieve to obtain a composite spray powder with uniform composition.

[0077] S3: Supersonic flame spray deposition: Using supersonic flame spray equipment, set the kerosene flow rate to 24.4L / h and the oxygen flow rate to 810m 3 / h, powder feeding rate 41g / min, deposition on the substrate surface preheated to 196℃ at a spray distance of 304mm, spraying in 4.2 passes, single layer thickness controlled to 42μm, interlayer cooling temperature ≤80℃ to avoid thermal stress accumulation;

[0078] S4. Laser Remelting and Surface Densification: The coating was remelted using a fiber laser with a spot diameter of 3.2 mm, a scan rate of 13 mm / s, and an overlap ratio of 36%. Argon gas curtain protection was used with a gas flow rate of 21 L / min and a controlled cooling rate of 68°C / s.

[0079] S5: Precision post-processing and surface finishing: The coating is placed in a vacuum annealing furnace at 216°C for 3.2 hours to eliminate internal stress, and then mechanically polished with a 1220-grit sand belt to reduce the surface roughness to Ra ≤ 0.8 μm. Finally, a 2.2 μm thick coating of heptadecafluorodecyltrimethoxysilane is sprayed on the coating and cured at 138°C for 26 minutes to form an anti-fingerprint and pollution-resistant inert surface.

[0080] Example 4

[0081] A highly wear-resistant stainless steel-based composite coating, comprising the following raw materials in parts by weight: 20.0 parts of dumbbell-shaped silver-doped silicon carbide filler, 15.0 parts of sea urchin-shaped titanium dioxide filler, 30.0 parts of 304 stainless steel powder, 30.0 parts of NiCrBSi nickel-based self-soluble alloy powder, 3.0 parts of boron oxide filler, 15.0 parts of nano-alumina filler, 10.0 parts of nano-zirconia filler, 5.0 parts of boron nitride filler, and 3.0 parts of rare earth oxide;

[0082] The preparation method of the dumbbell-shaped silver-doped silicon carbide filler of the present embodiment is as follows: 50.0 parts of glucose and 10.0 parts of tetraethoxysilane are used as raw materials and mixed in a mass ratio of 5:1, the mixed raw materials are placed in a stirring kettle, the stirring rate is 800 rpm, and the stirring time is 60 minutes until a uniform solution is formed, then 5.0 parts of 0.01 mol / L hydrochloric acid are added to the solution, the pH is adjusted to 5.0, and the stirring rate is maintained at 500 rpm for 40 minutes to form a uniform gel, the obtained gel solution is heated to 80°C, the temperature is increased at a heating rate of 5°C / min, the holding time is 24 hours, and constant temperature stirring is maintained at 80°C until the solvent evaporates to form a solid precursor, the precursor is placed in a vacuum drying oven, and dried at a temperature of 120°C for 12 hours to obtain a carbon-silicon composite precursor powder, and the dried The resulting powder was redispersed in 120 parts of ethanol and stirred at a stirring rate of 800 rpm for 30 minutes to form a suspension. Subsequently, 4.5 parts of 0.05 mol / L silver nitrate solution were slowly added and stirred at a constant temperature of 40°C for 45 minutes. The mixture was then transferred to a vacuum drying oven and dried at 80°C to constant weight. The solid powder was collected and placed in a tube furnace. It was heated to 1600°C at a heating rate of 10°C / min under an argon atmosphere and kept warm for 240 minutes. After naturally cooling to room temperature, the product was immersed in a 1 mol / L hydrochloric acid solution for 60 minutes for acid washing. The product was separated by a centrifuge at 8000 rpm for 10 minutes. The precipitate was washed with deionized water 5 times, each time with an amount of 5 times the volume of the precipitate. Finally, it was dried in a vacuum drying oven at 120°C for 12 hours to obtain a dumbbell-shaped silver-doped silicon carbide filler.

[0083] The dumbbell-shaped silver-doped silicon carbide filler of this embodiment has an average length of 600 nm, an average diameter of the neck of 200 nm, and an average diameter of the end of 400 nm.

[0084] The silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler of this embodiment is 3.0 at.%.

[0085] The preparation method of the sea urchin-shaped titanium dioxide filler in this embodiment is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol are mixed at a volume ratio of 0.5:40:50, the mixture is placed in a stirring container and stirred at a speed of 600 rpm for 30 minutes, and then transferred to an ultrasonic device and treated at a frequency of 60 kHz for 10 minutes to obtain a uniform dispersion system. The dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, heated to 200°C at a speed of 5°C / min and kept warm for 16 hours. The reaction is completed. After completion, the product was cooled to 30°C at a rate of 5°C / min, and then 0.5M hydrochloric acid was added dropwise to the coolant to adjust the pH to 7. The product was centrifuged at 10,000 rpm for 10 minutes to obtain a precipitate. The precipitate was washed 5 times with a 0.1 mol / L hydrochloric acid / deionized water mixture with a volume ratio of 1:1, with each amount of 50 ml. The precipitate was dried in a vacuum drying oven at 80°C for 16 hours, transferred to a tubular furnace, heated to 600°C at a rate of 10°C / min, and calcined for 120 minutes. Finally, the sea urchin-shaped titanium dioxide filler was obtained after grinding.

[0086] The average diameter of the sea urchin-shaped titanium dioxide filler in this embodiment is 4.5 μm, and the thorn-like branches on its surface are composed of 200 nm nano-scale titanium dioxide whiskers.

[0087] The rare earth oxide in this embodiment is lanthanum oxide.

[0088] The method for preparing a highly wear-resistant stainless steel-based composite coating of this embodiment comprises the following steps:

[0089] S1. Substrate pretreatment: Cold-rolled low-carbon steel and aluminum alloy plates were mechanically sandblasted using 120-mesh brown corundum sand at a pressure of 0.6 MPa and a surface roughness of Ra = 6.3 μm. Alkaline degreasing was then performed. The treated substrate was ultrasonically cleaned in an alkaline degreasing agent at 80°C and pH 12 for 10 min, followed by treatment in a 10 wt.% dilute hydrochloric acid solution at room temperature for 60 s. The substrate was then rinsed with water and dried to complete the pretreatment.

[0090] S2. Raw material mixing and powder preparation: dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler and rare earth oxide were put into a three-dimensional mixer and uniformly mixed at 25 rpm under argon protection for 90 minutes. The mixture was then sieved three times through a 200-mesh sieve to obtain a composite spray powder with uniform composition.

[0091] S3: Supersonic flame spray deposition: Use supersonic flame spray equipment, set the kerosene flow rate to 26L / h and the oxygen flow rate to 850m 3 / h, powder feeding rate 45g / min, deposition on the substrate surface preheated to 220℃ at a spray distance of 320mm, spraying in 5 passes, single layer thickness controlled to 50μm, interlayer cooling temperature ≤80℃ to avoid thermal stress accumulation;

[0092] S4. Laser Remelting and Surface Densification: The coating was remelted using a fiber laser with a spot diameter of 4 mm, a scan rate of 15 mm / s, and an overlap ratio of 40%. Argon gas curtain protection was used with a gas flow rate of 25 L / min and a controlled cooling rate of 80°C / s.

[0093] S5: Precision post-processing and surface finishing: The coating is placed in a vacuum annealing furnace at 240°C for 4 hours to eliminate internal stress, and then mechanically polished with a 1500-grit sand belt to reduce the surface roughness to Ra ≤ 0.8μm. Finally, a coating of 17-fluorodecyltrimethoxysilane is sprayed with a thickness of 3.0μm and cured at 150°C for 30 minutes to form an anti-fingerprint and pollution-resistant inert surface.

[0094] Comparative Example 1

[0095] The method is basically the same as Example 1, except that the dumbbell-shaped silver-doped silicon carbide filler is not added.

[0096] Comparative Example 2

[0097] The method is basically the same as Example 1, except that no sea urchin-shaped titanium dioxide filler is added.

[0098] Comparative Example 3

[0099] The method is basically the same as Example 1, except that the NiCrBSi nickel-based self-soluble alloy powder is not added.

[0100] Comparative Example 4

[0101] The method is basically the same as Example 1, except that the silicon carbide filler used is not doped with silver.

[0102] Comparative Example 5

[0103] The method is basically the same as Example 1, except that the content of the boron oxide filler is reduced to 0.1 parts.

[0104] Comparative Example 6

[0105] The method is basically the same as Example 1, except that no nano-alumina and nano-zirconia fillers are added.

[0106] Comparative Example 7

[0107] It is basically the same as Example 1, except that the sprayed coating is not subjected to laser remelting treatment.

[0108] Comparative Example 8

[0109] The process is basically the same as Example 1, except that the spraying temperature is lowered to 120°C.

[0110] Performance testing:

[0111] Hardness: To evaluate the hardness of the coatings of the present invention, a Vickers microhardness tester was used according to ASTM E92. A 300g load was applied to the specimen surface for 15 seconds, and the diagonal length of the indentation was measured to calculate the Vickers hardness value (HV).

[0112] Wear resistance testing: Using ASTM G65, a dry sand rubber wheel abrasion tester was used to compare the mass loss of the coating of the present invention with that of a control sample without reinforcing filler. A load of 130 N was applied, and the sample was rotated at 200 rpm for 30 minutes. The mass change was measured.

[0113] Antibacterial performance test: According to ISO 22196, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were selected as test bacteria. The bacterial liquid was inoculated on the coating surface and cultured at 37°C for 24 hours before measuring the colony reduction rate.

[0114] Coating adhesion test: Using ASTM C633 standard, the coating specimen was bonded to a tensile test bar using epoxy adhesive. A tensile load was applied until the coating peeled off, and the adhesion strength (MPa) was recorded.

[0115] The properties of the coatings of Examples 1 to 4 and Comparative Examples 1 to 8 are summarized in Table 1.

[0116] Table 1 Summary of coating properties of Examples 1 to 7 and Comparative Examples 1 to 4

[0117]

[0118]

[0119] In summary, the hardness significantly increased with the addition of dumbbell-shaped silver-doped silicon carbide fillers. The reinforcing effect of this filler enhanced the coating's compactness and mechanical stress resistance. Wear resistance was significantly influenced by filler optimization. The addition of NiCrBSi alloy improved the coating's adhesion and wear resistance, while the coating without laser remelting exhibited a significant increase in wear rate due to its higher porosity. Antibacterial properties were primarily influenced by the silver-doped silicon carbide filler. The silver ion release from this filler effectively inhibited bacterial growth, significantly enhancing the coating's antibacterial efficacy. The coating's adhesion was dependent on the presence of NiCrBSi alloy. The alloy's self-fluxing properties enhanced the metallurgical bond between the coating and the substrate, while the coating's lack of this component significantly reduced its bonding strength. Overall, the synergistic effect of the dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, NiCrBSi alloy, boron oxide, nano-alumina, and zirconium oxide fillers effectively enhanced the coating's hardness, wear resistance, antibacterial properties, and adhesion, resulting in excellent overall performance for high-performance applications.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that any equivalent structural changes made based on the contents of the present invention's description and drawings under the concept of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A highly wear-resistant stainless steel-based composite coating, characterized in that: The invention comprises the following raw materials in parts by weight: 10.0-20.0 parts of dumbbell-shaped silver-doped silicon carbide filler, 5.0-15.0 parts of sea urchin-shaped titanium dioxide filler, 25.0-30.0 parts of 304 stainless steel powder, 20.0-30.0 parts of NiCrBSi nickel-based self-soluble alloy powder, 0.5-3.0 parts of boron oxide filler, 5.0-15.0 parts of nano-alumina filler, 3.0-10.0 parts of nano-zirconia filler, 2.0-5.0 parts of boron nitride filler, and 0.5-3.0 parts of rare earth oxide; The dumbbell-shaped silver-doped silicon carbide filler is prepared by a sol-gel method combined with high-temperature carbonization and acid washing purification processes; The sea urchin-shaped titanium dioxide is prepared by a hydrothermal synthesis method combined with high-temperature calcination; The composite coating is prepared by the following key process: after the above raw materials are mixed to prepare a composite spray powder, it is deposited on the surface of a substrate preheated to 160-220° C. using a supersonic flame spraying device, with the kerosene flow rate set at 22-26 L / h, the oxygen flow rate at 750-850 m³ / h, the powder feeding rate at 35-45 g / min, the spraying distance at 280-320 mm, and the spraying in 3-5 passes; The coating was then remelted using a fiber laser with parameters set as a spot diameter of 2-4 mm, a scanning rate of 10-15 mm / s, and an overlap rate of 30-40%. Argon curtain protection was used simultaneously with a gas flow rate of 15-25 L / min and a controlled cooling rate of 50-80°C / s.

2. A highly wear-resistant stainless steel-based composite coating according to claim 1, characterized in that: The preparation method of the dumbbell-shaped silver-doped silicon carbide filler is as follows: 10.0-50.0 parts of glucose and 10.0 parts of tetraethoxysilane are used as raw materials, mixed in a mass ratio of (1-5):1, the mixed raw materials are placed in a stirring tank, the stirring rate is 500-800 rpm, and the stirring time is 30-60 min until a uniform solution is formed, then 2.0-5.0 parts of 0.01 mol / L hydrochloric acid are added to the solution, the pH is adjusted to 3.0-5.0, and the stirring rate is maintained at 300-500 rpm for 20-40 min to form a uniform gel, the obtained gel solution is heated to 50-80°C, the temperature is increased at a heating rate of 2-5°C / min, the holding time is 12-24 h, and constant temperature stirring is maintained at 50-80°C until the solvent evaporates to form a solid precursor, and the precursor is placed in a vacuum drying oven and dried at a temperature of 80-120°C for 6-12 h, obtain carbon-silicon composite precursor powder, redisperse the dried powder in 100-120 parts of ethanol, stir at a stirring rate of 500-800 rpm for 20-30 min to form a suspension, then slowly add 2.0-4.5 parts of 0.05 mol / L silver nitrate solution, keep stirring at a constant temperature of 25-40 ° C for 30-45 min, then transfer the mixed solution to a vacuum drying oven, dry at 60-80 ° C to constant weight, collect the solid powder and place it in a tube furnace, heat to 1200-1600 ° C at a heating rate of 5-10 ° C / min under argon atmosphere, keep warm for 120-240 min, cool naturally to room temperature, immerse the product in 1 mol / L hydrochloric acid solution for 30-60 min for acid washing, and separate it by centrifuge at 5000-8000 rpm for 5-10 The precipitate was washed with deionized water for 3 to 5 times, each time using 3 to 5 times the volume of the precipitate, and finally dried in a vacuum drying oven at 80 to 120 °C for 6 to 12 h to obtain dumbbell-shaped silver-doped silicon carbide filler.

3. A highly wear-resistant stainless steel-based composite coating according to claim 1 or 2, characterized in that: The dumbbell-shaped silver-doped silicon carbide filler has an average length of 200-600 nm, an average diameter of the neck of 65-200 nm, and an average diameter of the end of 90-400 nm.

4. A highly wear-resistant stainless steel-based composite coating according to claim 3, characterized in that: The silver doping amount of the dumbbell-shaped silver-doped silicon carbide filler is 1.5-3.0 at.%.

5. The high wear-resistant stainless steel-based composite coating according to claim 1, characterized in that: The preparation method of the sea urchin-shaped titanium dioxide filler is as follows: tetrabutoxytitanium, 1 mol / L sodium hydroxide aqueous solution and ethylene glycol are used as raw materials, and are mixed in a volume ratio of (0.3~0.5 mL): (20~40 mL): (30~50 mL), the mixed solution is placed in a stirring container and stirred at a rate of 300~600 rpm for 10~30 min, and then transferred to an ultrasonic device, and treated at a frequency of 40~60 kHz for 3~10 min to obtain a uniform dispersion system, and the dispersion system is injected into a polytetrafluoroethylene hydrothermal reactor, and the temperature is increased to 160~200°C at 2~5°C / min and kept warm for 8~16 h. After the reaction is completed, it is cooled to 25~30°C at 2~5°C / min, and then 0.1~0.5 M hydrochloric acid is added dropwise to the coolant to adjust the pH to 6~7, and the precipitate is obtained by centrifugation at 5000~10000 rpm for 5~10 min. The precipitate was washed 3 to 5 times with a mixture of mol / L hydrochloric acid and deionized water, each time using 30 to 50 ml. The precipitate was dried in a vacuum drying oven at 50 to 80°C for 8 to 16 h, then transferred to a tube furnace and heated to 500 to 600°C at a rate of 2 to 10°C / min and calcined for 60 to 120 min. Finally, the sea urchin-shaped titanium dioxide filler was obtained after grinding.

6. The high wear-resistant stainless steel-based composite coating according to claim 1, characterized in that: The average diameter of the sea urchin-shaped titanium dioxide filler is 1.5-4.5 μm, and the thorn-like branches on its surface are composed of nano-scale titanium dioxide whiskers of 100-200 nm.

7. The high wear-resistant stainless steel-based composite coating according to claim 1, characterized in that: The rare earth oxide is yttrium oxide or lanthanum oxide.

8. A method for preparing a highly wear-resistant stainless steel-based composite coating according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Substrate Pretreatment: Cold-rolled mild steel or aluminum alloy plates were mechanically sandblasted using 80-120 mesh brown corundum sand at a pressure of 0.4-0.6 MPa to a surface roughness of 3.2-6.3 μm Ra. Alkaline degreasing was then performed. The treated substrate was ultrasonically cleaned in an alkaline degreasing agent at 60-80°C and a pH of 10-12 for 5-10 min. The substrate was then treated in a 10 wt.% dilute hydrochloric acid solution at room temperature for 30-60 s. The substrate was then rinsed with water and dried to complete the pretreatment. S2. Raw material mixing and powder preparation: Dumbbell-shaped silver-doped silicon carbide filler, sea urchin-shaped titanium dioxide filler, 304 stainless steel powder, NiCrBSi nickel-based self-soluble alloy powder, boron oxide filler, nano-alumina filler, nano-zirconia filler, boron nitride filler, and rare earth oxide were placed in a three-dimensional mixer and uniformly mixed at 15-25 rpm under argon protection for 60-90 minutes. The mixture was then sieved three times through a 150-200 mesh sieve to obtain a uniform composite spray powder. S3: Supersonic flame spray deposition: Using supersonic flame spray equipment, multi-pass deposition is performed on the preheated substrate surface, divided into 3 to 5 spray passes, and the inter-pass cooling temperature is ≤80℃ to avoid thermal stress accumulation; S4. Laser Remelting and Surface Densification: The coating is remelted using a fiber laser while using a shielding gas to control the cooling rate. S5: Precision post-processing and surface finishing: The coating is placed in a vacuum annealing furnace at 180-240°C for 2-4 hours to eliminate internal stress. It is then mechanically polished with an 800-1500 grit sand belt to reduce the surface roughness to Ra ≤ 0.8 μm. Finally, a coating of 17-fluorodecyltrimethoxysilane is sprayed on with a thickness of 1.0-3.0 μm. The coating is cured at 120-150°C for 20-30 minutes to form an inert surface that is anti-fingerprint and stain-resistant.

9. Use of the high-wear-resistant stainless steel-based composite coating according to any one of claims 1 to 7 or the high-wear-resistant stainless steel-based composite coating prepared by the preparation method according to claim 8 on a cabinet door panel.

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