A high-performance scratch-resistant, wear-resistant and corrosion-resistant nylon material substituting steel with plastic

Abstract

The present invention relates to the field of nylon materials, and provides a high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-substitute steel nylon material, which solves the problem of insufficient scratch-resistant, wear-resistant, and corrosion-resistant performance of existing nylon materials. The material is composed of surface-modified calcium fluoride @ alumina whisker filler, polytetrafluoroethylene-coated boron nitride particles, nylon matrix resin, compatibilizer, antioxidant, and lubricant. Each key component adopts a special preparation process to improve its dispersibility and interface compatibility, thereby significantly enhancing the mechanical properties, wear resistance, and chemical stability of the composite material. The material is suitable for metal replacement applications in the fields of automobiles, machinery, etc., achieves excellent scratch resistance and wear resistance, solves the problem of poor corrosion resistance of nylon materials, and has wide application value.

Description

Technical Field

[0001] The invention relates to the field of nylon materials, and in particular to a high-performance, scratch-resistant, wear-resistant, and corrosion-resistant nylon material using plastic instead of steel. Background Art

[0002] In high-intensity operating environments such as automotive manufacturing, rail transit, and construction machinery, metal components are widely used in core applications such as load-bearing, friction, and connection. However, their heavy weight, high processing costs, and susceptibility to corrosion are becoming increasingly prominent. Replacing steel with plastics, particularly nylon, has become a key development direction in the trend toward lightweighting and functional integration. For key components such as gears, bearings, and structural supports, the materials must not only possess excellent mechanical strength but also maintain stable scratch, wear, and corrosion resistance under long-term friction, impact, and complex chemical media. Under extreme operating conditions such as high humidity, high salt levels, and high temperatures, the material's surface damage resistance and chemical stability are directly related to the product's service life and safety. Therefore, the development of nylon composite materials with high-performance scratch, wear, and corrosion resistance is crucial for improving equipment reliability, extending maintenance cycles, and reducing overall operating costs. Furthermore, the widespread use of such materials can further promote the development of lightweight engineering material systems, expand the application boundaries of plastic-to-steel substitution, and facilitate the transformation of industrial manufacturing towards efficiency, greenness, and intelligence.

[0003] At present, although engineering plastics based on nylon have initially achieved the goal of replacing steel with plastic in multiple industrial fields due to their good processability and mechanical properties, existing materials still have significant deficiencies when dealing with high-intensity friction and complex corrosion environments, limiting their further application in key components. For example, Chinese patent No. CN117844235B discloses a high-wear-resistant nylon material. Although some mechanical properties of the material are improved by adding fillers, no effective breakthrough has been achieved in terms of scratch resistance, wear resistance and corrosion resistance. In particular, surface wear or performance degradation is prone to occur under high-frequency friction or acid-base corrosion environments. The main reason for this problem is that traditional reinforcement methods are mostly limited to single inorganic fillers, and the interface compatibility and microstructure regulation are insufficient, making it difficult to simultaneously take into account the synergistic improvement of wear resistance and corrosion resistance. In addition, most existing technologies also have obvious shortcomings in filler dispersibility, surface modification effectiveness and composite system stability, resulting in significant performance degradation of the material during long-term service. Therefore, there is an urgent need to develop a new type of nylon composite material with a reasonable structural design and significant synergistic reinforcement effect of components, so as to achieve a comprehensive improvement in key indicators such as high performance scratch resistance, wear resistance and corrosion resistance, and fundamentally meet the engineering needs of replacing steel with plastic in complex application environments. Summary of the Invention

[0004] (1) Technical problems solved

[0005] The purpose of the present invention is to provide a high-performance scratch-resistant, wear-resistant and corrosion-resistant nylon material using plastic instead of steel, so as to solve the problem that the current nylon material is insufficient in scratch resistance, wear resistance and corrosion resistance.

[0006] (2) Technical solution

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

[0008] A high-performance, scratch-resistant, wear-resistant, and corrosion-resistant nylon material using plastic instead of steel comprises the following components, measured by weight: 5.0-15.0 parts of surface-modified calcium fluoride and alumina whisker filler, 3.5-8.0 parts of polytetrafluoroethylene-coated boron nitride particles, 50.0-90.0 parts of nylon matrix resin, 1.0-3.0 parts of a compatibilizer, 0.1-0.5 parts of an antioxidant, and 0.4-1.0 parts of a lubricant.

[0009] The surface-modified calcium fluoride@alumina whisker filler is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane;

[0010] The calcium fluoride@aluminum oxide whiskers are composed of aluminum oxide whiskers and a calcium fluoride nanolayer supported on the surface of the aluminum oxide whiskers;

[0011] The polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles;

[0012] Furthermore, the surface-modified calcium fluoride@aluminum oxide whiskers have an average diameter of 500-4500 nm and an average length of 4.5-7.0 μm; the thickness of the calcium fluoride nanolayer is 80-150 nm;

[0013] Furthermore, the preparation method of the surface-modified calcium fluoride @ alumina whisker filler is as follows: 100 parts by weight of calcium fluoride @ alumina whisker filler are dispersed in 300 to 500 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 3:1 to 1:1; after ultrasonic treatment for 10 to 30 minutes until uniform dispersion, 0.5 to 3 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent are added; the mixture is stirred at 50 to 90°C at a stirring rate of 200 to 500 rpm for 3 to 8 hours; the solid and liquid phases are then separated by a vacuum filtration device; the solid phase is retained and washed with ethanol 3 to 5 times to remove the unreacted coupling agent; and the product is finally dried in an oven at 80 to 120°C for 2 to 4 hours to obtain the surface-modified calcium fluoride @ alumina whisker filler.

[0014] Furthermore, the preparation method of the calcium fluoride @ alumina whisker is as follows: 100 parts of alumina whiskers are dispersed in 200-500 parts of deionized water by weight, ultrasonically treated for 10-60 minutes to form a uniform suspension, 5-20 parts of calcium chloride and 3-15 parts of an aqueous solution of ammonium fluoride with a concentration of 0.1-1.5 mol / L are added in sequence under continuous stirring at a stirring rate of 200-800 rpm, the pH is adjusted to 8-11, and an in-situ crystallization precipitation reaction is carried out at 50-80°C for 60-180 minutes. After the reaction is completed, the mixture is washed with deionized water 3-5 times and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 80-120°C for 2-6 hours to obtain a calcium fluoride @ alumina whisker composite powder.

[0015] Furthermore, the preparation method of the alumina whiskers is as follows: in parts by weight, 5 to 20 parts of aluminum nitrate are dissolved in 50 to 200 parts of deionized water to form an aluminum salt solution, 3 to 8 parts of polyethylene glycol are added and mixed uniformly at a stirring rate of 200 to 800 rpm, 3 to 15 parts of 5 wt.% ammonia water are slowly added dropwise to adjust the pH of the solution to 8 to 12 to form aluminum hydroxide colloid, the mixed solution is transferred to a high-pressure hydrothermal reactor and reacted at 150 to 250° C. for 6 to 24 hours, after the reaction, cooled to 25 to 60° C., the liquid phase is separated by vacuum filtration, and the solid phase is washed with deionized water 3 to 5 times to remove residual template and soluble ions, the retained solid phase is dried at 80 to 120° C. for 2 to 6 hours, and then placed in a calcining furnace and heated to 600 to 1000° C. at a heating rate of 2 to 10° C. / min and calcined for 2 to 6 hours to obtain alumina whiskers.

[0016] The present invention adopts the design of surface-modified calcium fluoride @ alumina whisker filler, which is mainly used to enhance the scratch resistance, wear resistance and corrosion resistance of nylon materials. By constructing a calcium fluoride @ alumina whisker structure with alumina whiskers as the skeleton and a calcium fluoride nanolayer on the surface, not only is the filler given excellent mechanical strength and thermal stability, but its chemical stability and interface functional properties in complex environments are also further improved. As the main reinforcing phase, alumina whiskers have good dimensional regularity and a high aspect ratio. They can effectively transfer stress and inhibit the expansion of microcracks in composite materials, significantly improving the material's scratch resistance and wear resistance. The introduction of the calcium fluoride nanolayer improves the reactivity and corrosion resistance of the whisker surface, providing a guarantee for the stable use of the material in corrosive media such as acids and alkalis. On this basis, the calcium fluoride @ alumina whiskers are surface-modified by 3,3,3-trifluoropropyltrimethoxysilane to further enhance their dispersibility and interface compatibility in the polar nylon matrix, so that the filler can form a uniform and stable distribution state in the resin system, thereby achieving the synergistic optimization of structural continuity and performance balance. This technical solution forms a composite synergistic effect in mechanical enhancement and chemical protection through multi-level regulation of the whisker structure and surface functionalization treatment, significantly improving the comprehensive service capability of nylon materials under various working conditions, and reflecting the systematic and efficient material construction strategy.

[0017] Furthermore, the preparation method of the polytetrafluoroethylene-coated boron nitride particles is as follows: 100 parts by weight of boron nitride particles are dispersed in 300-800 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 30-60 wt.%, and treated with an ultrasonic power of 300-1000 W for 15-90 min to form a uniform suspension system, 2.0-5.0 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly at a stirring rate of 300-1000 rpm, hydrochloric acid or ammonia water with a concentration of 5-10 wt% is added dropwise to adjust the pH to 2-5, the temperature is raised to 60-100 ° C and the reaction is kept at this temperature for 2-4 h to allow polytetrafluoroethylene to be in situ deposited on the particle surface to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles are removed by vacuum filtration, and the solid phase is retained and ultrasonically washed with anhydrous ethanol for 3-5 times to remove surfactants and free ions. The product is then transferred to an oven and dried at 100-150°C for 3-12 h to obtain a primary coated powder. The powder is then placed in a tube furnace under nitrogen protection and heated to 320-400°C at a heating rate of 2-10°C / min and sintered for 1-3 h to densify the polytetrafluoroethylene film layer, ultimately obtaining polytetrafluoroethylene-coated boron nitride particles.

[0018] Furthermore, the preparation method of the boron nitride particles is as follows: in parts by weight, 100 parts of hexagonal boron nitride raw material powder with an initial particle size of 5-20 μm and a purity of ≥99% is mixed with 500-2000 parts of zirconia ball milling media with a diameter of 5 mm, and wet ball milling is performed using a planetary ball mill with a ball-to-material ratio of 5:1-20:1 and a rotation speed of 200-600 rpm, and 100-500 parts of deionized water and 2-5 parts of polyvinyl pyrrolidone are added to form a slurry with a solid-liquid ratio of 1:1-1:5, the ball mill filling rate is controlled to be 50-70% and the ball milling time is 10-20 h, the temperature is maintained at ≤60°C during the process to avoid damage to the boron nitride structure, and after the ball milling is completed, the ball milling media is removed by centrifugation and a boron nitride suspension with a particle size of ≤3 μm is retained, and the suspension is then vacuum dried at 60-100°C for 4-12 h to remove the dispersion medium, then use a jet mill to deagglomerate the product at a pressure of 0.5~1.2 MPa, and finally heat it to 800~1200°C at a heating rate of 5~10°C / min in a nitrogen atmosphere and calcine it for 1~2 h to obtain boron nitride particles.

[0019] Furthermore, the average diameter of the polytetrafluoroethylene-coated boron nitride particles is 200-800 nm; the thickness of the polytetrafluoroethylene coating layer is 30-80 nm;

[0020] Furthermore, the nylon matrix resin is a mixture of PA6 and PA66 in a mass ratio of (60-80): (40-20);

[0021] Furthermore, the compatibilizer is polyethylene grafted maleic anhydride;

[0022] Further, the antioxidant is antioxidant 1010;

[0023] Furthermore, the lubricant is ethylene bisstearamide.

[0024] The present invention adopts a design of polytetrafluoroethylene-coated boron nitride particles, which is mainly used to enhance the scratch resistance, wear resistance and corrosion resistance of nylon materials. The initial hexagonal boron nitride raw material is prepared into boron nitride particles with a reasonable particle size distribution through wet ball milling, deagglomeration and high-temperature calcination, and a polytetrafluoroethylene coating is deposited in situ on the surface. This not only gives the boron nitride particles good lubricity and thermal stability, but also significantly improves its dispersibility and interfacial compatibility in the nylon matrix. The polytetrafluoroethylene coating forms a dense coating structure during the high-temperature sintering process, which can effectively limit the agglomeration of boron nitride, promote its uniform distribution in the polymer matrix, and form a stable lubricated interface during the use of the material, thereby reducing the friction coefficient and slowing surface wear. At the same time, boron nitride itself has excellent chemical inertness and corrosion resistance, which can significantly improve the stability of the composite material in acidic, alkaline or wet and hot environments. By adjusting the coating thickness and particle size, dual regulation of the interface microstructure and macroscopic performance is achieved, so that the material can still maintain good functional stability under the influence of long-term friction impact and external corrosive media. Furthermore, the present invention incorporates polyethylene-grafted maleic anhydride as a compatibilizer into the nylon matrix, fostering a stronger interfacial bond between the filler and the matrix, improving the overall structural integrity of the composite system. Simultaneously, the synergistic introduction of antioxidant 1010 and ethylene bisstearamide further enhances the material's antioxidant capacity and processing fluidity. Within the overall design, the polytetrafluoroethylene-coated boron nitride particles not only provide lubrication and stability but also form a synergistic effect with other additives and the nylon matrix, achieving multiple improvements in the material's scratch, wear, and corrosion resistance. This fully embodies the design concept of structural optimization and performance integration for multiphase composite materials.

[0025] (3) Beneficial technical effects

[0026] 1. This invention significantly improves the comprehensive performance of nylon materials in high-wear and highly corrosive environments through the coordinated design of structural reinforcement and surface modification of calcium fluoride and aluminum oxide whiskers, addressing the poor durability of existing materials and possessing excellent engineering application value.

[0027] 2. This invention achieves significant improvements in the scratch resistance, wear resistance, and corrosion resistance of nylon materials under complex working conditions through the collaborative design of polytetrafluoroethylene-coated boron nitride particles and a variety of additives, and has excellent interface stability and application reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a morphology diagram of the aluminum oxide whiskers prepared in Example 1 of the present invention.

[0029] Figure 2 This is the XRD phase analysis diagram of the aluminum oxide whiskers prepared in Example 1 of the present invention.

[0030] Figure 3 This is a morphology picture of the modified calcium fluoride@alumina whisker filler prepared in Example 1 of the present invention.

[0031] Figure 4 This is the XRD phase analysis diagram of the modified calcium fluoride@alumina whisker filler prepared in Example 1 of the present invention.

[0032] Figure 5 This is a morphology diagram of the boron nitride particles prepared in Example 1 of the present invention.

[0033] Figure 6 This is the XRD phase analysis diagram of the boron nitride particles prepared in Example 1 of the present invention.

[0034] Figure 7 This is a morphology picture of polytetrafluoroethylene-coated boron nitride particles 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: A high-performance, scratch-resistant, wear-resistant, and corrosion-resistant plastic-substitute steel nylon material, comprising the following components, in parts by weight: 5.0 parts of surface-modified calcium fluoride @ alumina whisker filler, 3.5 parts of polytetrafluoroethylene-coated boron nitride particles, 50.0 parts of nylon matrix resin, 1.0 part of a compatibilizer, 0.1 part of an antioxidant, and 0.4 part of a lubricant.

[0037] The surface-modified calcium fluoride@alumina whisker filler of this embodiment is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane; the calcium fluoride@alumina whiskers are composed of alumina whiskers and a calcium fluoride nanolayer supported on the surface of the alumina whiskers; the polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles;

[0038] The surface-modified calcium fluoride@aluminum oxide whiskers of this embodiment have an average diameter of 500 nm and an average length of 4.5 μm; the thickness of the calcium fluoride nanolayer is 80 nm;

[0039] The preparation method of the surface-modified calcium fluoride @ alumina whisker filler of this embodiment is as follows: 100 parts by weight of calcium fluoride @ alumina whisker filler are dispersed in 300 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 3:1. After ultrasonic treatment for 10 minutes until uniform dispersion, 0.5 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent is added, and the mixture is stirred at 50° C. and a stirring rate of 200 rpm for 3 hours. Subsequently, the solid and liquid phases are separated by a vacuum filtration device, the solid phase is retained and washed with ethanol three times to remove unreacted coupling agent, and the product is finally dried in an oven at 80° C. for 2 hours to obtain the surface-modified calcium fluoride @ alumina whisker filler.

[0040] The preparation method of calcium fluoride @ alumina whiskers in this embodiment is as follows: 100 parts by weight of alumina whiskers are dispersed in 200 parts of deionized water, ultrasonically treated for 10 minutes to form a uniform suspension, 5 parts of calcium chloride and 3 parts of a 0.1 mol / L aqueous ammonium fluoride solution are sequentially added under continuous stirring at a stirring rate of 200 rpm, the pH is adjusted to 8, and an in-situ crystallization precipitation reaction is carried out at 50° C. for 60 minutes. After the reaction, the mixture is washed three times with deionized water and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 80° C. for 2 hours to obtain a calcium fluoride @ alumina whisker composite powder.

[0041] The preparation method of the aluminum oxide whiskers in this embodiment is as follows: in parts by weight, 5 parts of aluminum nitrate are dissolved in 50 parts of deionized water to form an aluminum salt solution, 3 parts of polyethylene glycol are added and mixed evenly at a stirring rate of 200 rpm, 3 parts of 5 wt.% ammonia water are slowly added dropwise to make the solution pH 8 to form aluminum hydroxide colloid, the mixed solution is transferred to a high-pressure hydrothermal reactor and reacted at 150°C for 6 hours, after the reaction, it is cooled to 25°C and the liquid phase is separated by vacuum filtration and the solid phase is washed 3 times with deionized water to remove residual template and soluble ions, the solid phase is retained and dried at 80°C for 2 hours, and then placed in a calcining furnace and heated to 600°C at a heating rate of 2°C / min and calcined for 2 hours to obtain aluminum oxide whiskers.

[0042] The preparation method of the polytetrafluoroethylene-coated boron nitride particles of this embodiment is as follows: 100 parts by weight of boron nitride particles are dispersed in 450 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 39 wt.%, and ultrasonically treated at a power of 510 W for 38 minutes to form a uniform suspension system; 2.9 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly at a stirring rate of 510 rpm; 7 wt.% hydrochloric acid or ammonia water is added dropwise to adjust the pH to 3; the temperature is raised to 72°C and the mixture is stirred at 510 rpm. The reaction was carried out at a constant temperature for 3 hours to allow polytetrafluoroethylene to be in situ deposited on the surface of the particles to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles were removed by vacuum filtration, and the solid phase was retained and ultrasonically washed four times with anhydrous ethanol to remove surfactants and free ions. The product was then transferred to an oven and dried at 115°C for 6 hours to obtain a primary coated powder. The powder was then placed in a tubular furnace under nitrogen protection and heated to 344°C at a heating rate of 4°C / min and sintered for 2 hours to densify the polytetrafluoroethylene film layer, ultimately obtaining polytetrafluoroethylene-coated boron nitride particles.

[0043] The preparation method of the boron nitride particles of this embodiment is as follows: 100 parts by weight of hexagonal boron nitride raw material powder with an initial particle size of 10 μm and a purity of ≥99% is mixed with 950 parts of zirconium oxide balls with a diameter of 5 mm as a ball milling medium, and wet ball milling is performed using a planetary ball mill at a ball-to-material ratio of 9.5:1 and a rotation speed of 320 rpm. 220 parts of deionized water and 3 parts of polyvinyl pyrrolidone are added to form a slurry with a solid-liquid ratio of 1:2.2. The filling rate of the ball mill is controlled to be 56% and the ball milling time is 13 hours. During the process, the temperature is maintained at ≤60°C to avoid damage to the boron nitride structure. After the ball milling, the ball milling medium is removed by centrifugation and a boron nitride suspension with a particle size of ≤3 μm is retained. The suspension is then vacuum dried at 72°C for 6 hours to remove the dispersion medium, and then deagglomerated by a jet mill at a pressure of 0.7 MPa. Finally, the boron nitride particles are obtained by heating to 920°C at a heating rate of 7°C / min in a nitrogen atmosphere and calcining for 1 hour.

[0044] The average diameter of the polytetrafluoroethylene-coated boron nitride particles of this embodiment is 380 nm; the thickness of the polytetrafluoroethylene coating is 45 nm;

[0045] The nylon matrix resin of this embodiment is a mixture of PA6 and PA66 in a mass ratio of 66:34;

[0046] In this embodiment, the compatibilizer is polyethylene grafted maleic anhydride; the antioxidant is antioxidant 1010; and the lubricant is ethylene bisstearamide.

[0047] Figure 1 and Figure 3The typical one-dimensional whisker-like structure of the aluminum oxide whiskers and the modified filler after composited with calcium fluoride in Example 1 of the present invention is shown, indicating that the prepared material has good morphological uniformity and structural continuity, which helps to enhance the mechanical properties and interface bonding of the composite material; Figure 2 and Figure 4 The XRD phase analysis diagrams of alumina whiskers and their modified composites show the characteristic diffraction peak of γ-Al2O3, confirming that the transition phase alumina with high specific surface area and active surface is formed under high-temperature calcination conditions, and the introduction of calcium fluoride does not change its crystal structure, reflecting good structural stability. Figure 5 and Figure 7 The micromorphology of boron nitride particles and their polytetrafluoroethylene coatings are shown. The particles are evenly distributed and have a moderate particle size, which is conducive to improving dispersibility and lubrication performance. Figure 6 The XRD spectrum of boron nitride shown in the figure shows a typical hexagonal structure diffraction peak, which further verifies that the boron nitride particles have a complete crystal structure. Figures 1 to 7 The characterization results jointly verified the successful preparation, structural integrity and good compatibility of the component materials in the present invention, providing strong support for the synergistic improvement of mechanical, wear resistance and chemical resistance in the composite system.

[0048] Example 2: A high-performance, scratch-resistant, wear-resistant, and corrosion-resistant plastic-substitute steel nylon material, comprising the following components, in parts by weight: 8 parts of surface-modified calcium fluoride @ alumina whisker filler, 4.9 parts of polytetrafluoroethylene-coated boron nitride particles, 62 parts of nylon matrix resin, 1.6 parts of a compatibilizer, 0.2 parts of an antioxidant, and 0.6 parts of a lubricant.

[0049] The surface-modified calcium fluoride@alumina whisker filler of this embodiment is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane; the calcium fluoride@alumina whiskers are composed of alumina whiskers and a calcium fluoride nanolayer supported on the surface of the alumina whiskers; the polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles;

[0050] The surface-modified calcium fluoride@aluminum oxide whiskers of this embodiment have an average diameter of 1700 nm and an average length of 5.3 μm; the thickness of the calcium fluoride nanolayer is 101 nm;

[0051] The preparation method of the surface-modified calcium fluoride @ alumina whisker filler of this embodiment is as follows: 100 parts by weight of calcium fluoride @ alumina whisker filler are dispersed in 360 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 2.4:1. After ultrasonic treatment for 16 minutes until uniform dispersion, 1.3 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent is added, and the mixture is stirred at 62° C. and a stirring rate of 290 rpm for 5 hours. Subsequently, the solid and liquid phases are separated by a vacuum filtration device, and the solid phase is retained and washed with ethanol four times to remove unreacted coupling agent. Finally, the product is dried in a 92° C. oven for 3 hours to obtain the surface-modified calcium fluoride @ alumina whisker filler.

[0052] The preparation method of calcium fluoride @ alumina whiskers in this embodiment is as follows: 100 parts by weight of alumina whiskers are dispersed in 290 parts of deionized water, and ultrasonically treated for 25 minutes to form a uniform suspension. 10 parts of calcium chloride and 7 parts of a 0.5 mol / L aqueous ammonium fluoride solution are then added sequentially under continuous stirring at a stirring rate of 380 rpm. The pH is adjusted to 9, and an in-situ crystallization precipitation reaction is carried out at 59° C. for 96 minutes. After the reaction, the mixture is washed four times with deionized water and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 92° C. for 3 hours to obtain a calcium fluoride @ alumina whisker composite powder.

[0053] The preparation method of the aluminum oxide whiskers in this embodiment is as follows: in parts by weight, 10 parts of aluminum nitrate are dissolved in 95 parts of deionized water to form an aluminum salt solution, 5 parts of polyethylene glycol are added and mixed evenly at a stirring rate of 380 rpm, 7 parts of 5 wt.% ammonia water are slowly added dropwise to adjust the pH of the solution to 9 to form aluminum hydroxide colloid, the mixed solution is transferred to a high-pressure hydrothermal reactor and reacted at 180° C. for 11 hours, and after the reaction, it is cooled to 36° C. and the liquid phase is separated by vacuum filtration, and the solid phase is washed 4 times with deionized water to remove residual template and soluble ions. The retained solid phase is dried at 92° C. for 3 hours, and then placed in a calcining furnace and heated to 720° C. at a heating rate of 4° C. / min and calcined for 3 hours to obtain aluminum oxide whiskers.

[0054] The preparation method of the polytetrafluoroethylene-coated boron nitride particles of this embodiment is as follows: 100 parts by weight of boron nitride particles are dispersed in 300 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 30 wt.%, and ultrasonically treated at a power of 300 W for 15 minutes to form a uniform suspension system. 2.0 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly at a stirring rate of 300 rpm. 5 wt.% hydrochloric acid or ammonia water is added dropwise to adjust the pH to 2. The temperature is raised to 60°C and the mixture is stirred for 15 minutes. The reaction was carried out at a constant temperature for 2 hours to allow polytetrafluoroethylene to be in situ deposited on the surface of the particles to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles were removed by vacuum filtration, and the solid phase was retained and ultrasonically washed three times with anhydrous ethanol to remove surfactants and free ions. The product was then transferred to an oven and dried at 100°C for 3 hours to obtain a primary coated powder. The powder was then placed in a tubular furnace under nitrogen protection and heated to 320°C at a heating rate of 2°C / min and sintered for 1 hour to densify the polytetrafluoroethylene film layer, ultimately obtaining polytetrafluoroethylene-coated boron nitride particles.

[0055] The boron nitride particles of this embodiment are prepared by mixing, by weight, 100 parts of hexagonal boron nitride raw material powder having an initial particle size of 5 μm and a purity of ≥99% with 500 parts of zirconia balls having a diameter of 5 mm as a ball milling medium, and wet ball milling is performed using a planetary ball mill at a ball-to-material ratio of 5:1 and a rotation speed of 200 rpm. 100 parts of deionized water and 2 parts of polyvinyl pyrrolidone are then added to form a slurry having a solid-liquid ratio of 1:1. The ball milling jar filling rate is controlled to be 50% and the ball milling time is controlled to be 10 hours. During the process, the temperature is maintained at ≤60°C to prevent structural damage of the boron nitride. After the ball milling is completed, the ball milling medium is removed by centrifugation and a boron nitride suspension having a particle size of ≤3 μm is retained. The suspension is then vacuum dried at 60°C for 4 hours to remove the dispersion medium, and then deagglomerated in a jet mill at a pressure of 0.5 MPa. Finally, the suspension is heated to 800°C at a heating rate of 5°C / min in a nitrogen atmosphere and calcined for 1 hour to obtain the boron nitride particles.

[0056] The average diameter of the polytetrafluoroethylene-coated boron nitride particles in this embodiment is 200 nm; the thickness of the polytetrafluoroethylene coating is 30 nm;

[0057] The nylon matrix resin of this embodiment is a mixture of PA6 and PA66 in a mass ratio of 60:40;

[0058] In this embodiment, the compatibilizer is polyethylene grafted maleic anhydride; the antioxidant is antioxidant 1010; and the lubricant is ethylene bisstearamide.

[0059] Example 3: A high-performance, scratch-resistant, wear-resistant, and corrosion-resistant plastic-substitute steel nylon material, comprising the following components, in parts by weight: 15.0 parts of surface-modified calcium fluoride @ alumina whisker filler, 8.0 parts of polytetrafluoroethylene-coated boron nitride particles, 90.0 parts of nylon matrix resin, 3.0 parts of compatibilizer, 0.5 parts of antioxidant, and 1.0 parts of lubricant.

[0060] The surface-modified calcium fluoride@alumina whisker filler of this embodiment is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane; the calcium fluoride@alumina whiskers are composed of alumina whiskers and a calcium fluoride nanolayer supported on the surface of the alumina whiskers; the polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles;

[0061] The surface-modified calcium fluoride@aluminum oxide whiskers of this embodiment have an average diameter of 4500 nm and an average length of 7.0 μm; the thickness of the calcium fluoride nanolayer is 150 nm;

[0062] The preparation method of the surface-modified calcium fluoride @ alumina whisker filler of this embodiment is as follows: 100 parts by weight of calcium fluoride @ alumina whisker filler are dispersed in 500 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 1:1. After ultrasonic treatment for 30 minutes until uniform dispersion, 3 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent are added. The mixture is stirred at 90° C. and a stirring rate of 500 rpm for 8 hours. The solid and liquid phases are then separated by a vacuum filtration device. The solid phase is retained and washed with ethanol five times to remove unreacted coupling agent. Finally, the product is dried in a 120° C. oven for 4 hours to obtain a surface-modified calcium fluoride @ alumina whisker filler.

[0063] The preparation method of calcium fluoride @ alumina whiskers in this embodiment is as follows: 100 parts by weight of alumina whiskers are dispersed in 500 parts of deionized water, and ultrasonically treated for 60 minutes to form a uniform suspension. 20 parts of calcium chloride and 15 parts of a 1.5 mol / L aqueous ammonium fluoride solution are then added sequentially under continuous stirring at a stirring rate of 800 rpm. The pH is adjusted to 11, and an in-situ crystallization precipitation reaction is carried out at 80° C. for 180 minutes. After the reaction, the mixture is washed with deionized water five times and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 120° C. for 6 hours to obtain a calcium fluoride @ alumina whisker composite powder.

[0064] The preparation method of the aluminum oxide whiskers in this embodiment is as follows: in parts by weight, 20 parts of aluminum nitrate are dissolved in 200 parts of deionized water to form an aluminum salt solution, 8 parts of polyethylene glycol are added and mixed uniformly at a stirring rate of 800 rpm, 15 parts of 5 wt.% ammonia water are slowly added dropwise to make the pH of the solution 12 to form aluminum hydroxide colloid, the mixed solution is transferred to a high-pressure hydrothermal reactor and reacted at 250°C for 24 hours, after the reaction, it is cooled to 60°C and the liquid phase is separated by vacuum filtration and the solid phase is washed with deionized water 5 times to remove residual template and soluble ions, the solid phase is retained and dried at 120°C for 6 hours, and then placed in a calcining furnace and heated to 1000°C at a heating rate of 10°C / min and calcined for 6 hours to obtain aluminum oxide whiskers.

[0065] The preparation method of the polytetrafluoroethylene-coated boron nitride particles of this embodiment is as follows: 100 parts by weight of boron nitride particles are dispersed in 800 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 60 wt.%, and ultrasonically treated at a power of 1000 W for 90 minutes to form a uniform suspension system. 5.0 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly at a stirring rate of 1000 rpm. 10 wt.% hydrochloric acid or ammonia water is added dropwise to adjust the pH to 5. The mixture is heated to 100°C. The reaction was carried out at a constant temperature for 4 hours to allow polytetrafluoroethylene to be in situ deposited on the surface of the particles to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles were removed by vacuum filtration, and the solid phase was retained and ultrasonically washed with anhydrous ethanol 5 times to remove surfactants and free ions. The product was then transferred to an oven and dried at 150°C for 12 hours to obtain a primary coated powder. The powder was then placed in a tubular furnace under nitrogen protection and heated to 400°C at a heating rate of 10°C / min and sintered for 3 hours to densify the polytetrafluoroethylene film layer, finally obtaining polytetrafluoroethylene-coated boron nitride particles.

[0066] The preparation method of the boron nitride particles of this embodiment is as follows: 100 parts by weight of hexagonal boron nitride raw material powder with an initial particle size of 20 μm and a purity of ≥99% is mixed with 2000 parts of zirconium oxide ball milling media with a diameter of 5 mm, and wet ball milling is performed using a planetary ball mill with a ball-to-material ratio of 20:1 and a rotation speed of 600 rpm. 500 parts of deionized water and 5 parts of polyvinyl pyrrolidone are added to form a slurry with a solid-liquid ratio of 1:5. The filling rate of the ball mill jar is controlled to be 70% and The ball milling time was 20 h, and the temperature was maintained at ≤60°C during the process to avoid damage to the boron nitride structure. After the ball milling, the ball milling medium was removed by centrifugation and a boron nitride suspension with a particle size of ≤3 μm was retained. The suspension was then vacuum dried at 100°C for 12 h to remove the dispersion medium, and then deagglomerated by a jet mill at a pressure of 1.2 MPa. Finally, the boron nitride particles were obtained by heating to 1200°C at a heating rate of 10°C / min in a nitrogen atmosphere and calcining for 2 h.

[0067] The average diameter of the polytetrafluoroethylene-coated boron nitride particles in this embodiment is 800 nm; the thickness of the polytetrafluoroethylene coating is 80 nm;

[0068] The nylon matrix resin of this embodiment is a mixture of PA6 and PA66 in a mass ratio of 80:20;

[0069] In this embodiment, the compatibilizer is polyethylene grafted maleic anhydride; the antioxidant is antioxidant 1010; and the lubricant is ethylene bisstearamide.

[0070] Example 4: A high-performance, scratch-resistant, wear-resistant, and corrosion-resistant plastic-substitute steel nylon material, comprising the following components, in parts by weight: 11 parts of surface-modified calcium fluoride @ alumina whisker filler, 6.2 parts of polytetrafluoroethylene-coated boron nitride particles, 74 parts of nylon matrix resin, 2.2 parts of a compatibilizer, 0.3 parts of an antioxidant, and 0.8 parts of a lubricant.

[0071] The surface-modified calcium fluoride@alumina whisker filler of this embodiment is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane; the calcium fluoride@alumina whiskers are composed of alumina whiskers and a calcium fluoride nanolayer supported on the surface of the alumina whiskers; the polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles;

[0072] The surface-modified calcium fluoride@aluminum oxide whiskers of this embodiment have an average diameter of 2900 nm and an average length of 6.0 μm; the thickness of the calcium fluoride nanolayer is 122 nm;

[0073] The surface-modified calcium fluoride@alumina whisker filler of this embodiment is prepared as follows: 100 parts by weight of calcium fluoride@alumina whisker filler are dispersed in 420 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 1.8:1. After ultrasonic treatment for 22 minutes until uniform dispersion, 2.0 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent are added, and the mixture is stirred at 74° C. and a stirring rate of 380 rpm for 6 hours. The solid and liquid phases are then separated by vacuum filtration. The solid phase is retained and washed four times with ethanol to remove unreacted coupling agent. Finally, the product is dried in an oven at 104° C. for 3 hours to obtain the surface-modified calcium fluoride@alumina whisker filler.

[0074] The preparation method of calcium fluoride @ alumina whiskers in this embodiment is as follows: 100 parts by weight of alumina whiskers are dispersed in 380 parts of deionized water, ultrasonically treated for 40 minutes to form a uniform suspension, 14 parts of calcium chloride and 10 parts of a 0.9 mol / L aqueous ammonium fluoride solution are sequentially added under continuous stirring at a stirring rate of 560 rpm, the pH is adjusted to 10, and an in-situ crystallization precipitation reaction is carried out at 68° C. for 132 minutes. After the reaction, the mixture is washed four times with deionized water and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 104° C. for 4 hours to obtain a calcium fluoride @ alumina whisker composite powder.

[0075] The preparation method of the aluminum oxide whiskers in this embodiment is as follows: in parts by weight, 14 parts of aluminum nitrate are dissolved in 140 parts of deionized water to form an aluminum salt solution, 6 parts of polyethylene glycol are added and mixed uniformly at a stirring rate of 560 rpm, 10 parts of 5 wt.% ammonia water are slowly added dropwise to make the pH of the solution 10 to form aluminum hydroxide colloid, the mixed solution is transferred to a high-pressure hydrothermal reactor and reacted at 210°C for 17 hours, after the reaction, it is cooled to 47°C, the liquid phase is separated by vacuum filtration, and the solid phase is washed 4 times with deionized water to remove residual template and soluble ions, the retained solid phase is dried at 104°C for 4 hours, and then placed in a calcining furnace and heated to 840°C at a heating rate of 7°C / min and calcined for 4 hours to obtain aluminum oxide whiskers.

[0076] The preparation method of the polytetrafluoroethylene-coated boron nitride particles of this embodiment is as follows: 100 parts by weight of boron nitride particles are dispersed in 600 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 48 wt.%, and ultrasonically treated at a power of 720 W for 60 minutes to form a uniform suspension system; 3.8 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly under a stirring rate of 720 rpm; 8 wt.% hydrochloric acid or ammonia water is added dropwise to adjust the pH to 4; the temperature is raised to 84°C and the mixture is stirred at 720 rpm. The reaction was carried out at a constant temperature for 3 hours to allow polytetrafluoroethylene to be in situ deposited on the surface of the particles to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles were removed by vacuum filtration, and the solid phase was retained and ultrasonically washed four times with anhydrous ethanol to remove surfactants and free ions. The product was then transferred to an oven and dried at 130°C for 8 hours to obtain a primary coated powder. The powder was then placed in a tubular furnace under nitrogen protection and heated to 368°C at a heating rate of 7°C / min and sintered for 2 hours to densify the polytetrafluoroethylene film layer, ultimately obtaining polytetrafluoroethylene-coated boron nitride particles.

[0077] The preparation method of the boron nitride particles of this embodiment is as follows: 100 parts by weight of hexagonal boron nitride raw material powder with an initial particle size of 14 μm and a purity of ≥99% is mixed with 1400 parts of zirconium oxide ball milling medium with a diameter of 5 mm, and wet ball milling is performed using a planetary ball mill with a ball-to-material ratio of 14:1 and a rotation speed of 440 rpm. 340 parts of deionized water and 4 parts of polyvinyl pyrrolidone are added to form a slurry with a solid-liquid ratio of 1:3.4. The filling rate of the ball mill is controlled to be 6 2% and the ball milling time is 16 hours. During the process, the temperature is maintained at ≤60°C to avoid damage to the boron nitride structure. After the ball milling, the ball milling medium is removed by centrifugation and a boron nitride suspension with a particle size of ≤3 μm is retained. The suspension is then vacuum dried at 84°C for 8 hours to remove the dispersion medium, and then deagglomerated by a jet mill at a pressure of 0.9 MPa. Finally, it is heated to 1040°C at a heating rate of 8°C / min in a nitrogen atmosphere and calcined for 2 hours to obtain boron nitride particles.

[0078] The average diameter of the polytetrafluoroethylene-coated boron nitride particles in this embodiment is 560 nm; the thickness of the polytetrafluoroethylene coating is 60 nm;

[0079] The nylon matrix resin of this embodiment is a mixture of PA6 and PA66 in a mass ratio of 72:28;

[0080] In this embodiment, the compatibilizer is polyethylene grafted maleic anhydride; the antioxidant is antioxidant 1010; and the lubricant is ethylene bisstearamide.

[0081] Comparative Example 1

[0082] The method is basically the same as Example 1, except that 3,3,3-trifluoropropyltrimethoxysilane coupling agent is not used for surface treatment during the preparation of the surface-modified calcium fluoride@alumina whisker filler, and unmodified calcium fluoride@alumina whisker filler is directly used.

[0083] Comparative Example 2

[0084] The method is basically the same as Example 1, except that no calcium fluoride layer is prepared on the surface of the calcium fluoride@aluminum oxide whiskers.

[0085] Comparative Example 3

[0086] The method is basically the same as Example 1, except that during the preparation of calcium fluoride@alumina whiskers, the pH value of the in-situ crystallization precipitation reaction is adjusted to 6, resulting in the inability of the calcium fluoride nanolayer to be uniformly deposited on the surface of the alumina whiskers.

[0087] Comparative Example 4

[0088] The method is basically the same as Example 1, except that the hydrothermal reaction temperature is lowered to 100° C. during the preparation of the alumina whiskers.

[0089] Comparative Example 5

[0090] The method is basically the same as Example 1, except that in the preparation of polytetrafluoroethylene-coated boron nitride particles, the sintering temperature is set to 280° C., resulting in incomplete melting and densification of the polytetrafluoroethylene coating layer.

[0091] Comparative Example 6

[0092] The process is basically the same as Example 1, except that in the ball-to-material ratio of the boron nitride particles is adjusted to 2:1, resulting in insufficient particle crushing efficiency and a final particle size greater than 3 μm.

[0093] Comparative Example 7

[0094] The method is basically the same as Example 1, except that during the surface modification process of the calcium fluoride@alumina whisker filler, the weight ratio of the mixed solvent of ethanol and water is changed to 5:1, which leads to an abnormal hydrolysis rate of the coupling agent and a reduced grafting rate.

[0095] Comparative Example 8

[0096] The method is basically the same as Example 1, except that the nylon matrix resin is only PA6.

[0097] Comparative Example 9

[0098] The process is basically the same as Example 1, except that the compatibilizer is replaced by pure polyethylene without maleic anhydride grafted thereto.

[0099] Comparative Example 10

[0100] The method is basically the same as Example 1, except that the boron nitride particles are not coated with polytetrafluoroethylene.

[0101] Comparative Example 11

[0102] The method is basically the same as Example 1, except that the thickness of the calcium fluoride layer in the calcium fluoride@alumina whisker filler is controlled to be 40 nm.

[0103] Performance testing:

[0104] Scratch resistance testing: An instrumented scratch tester is used in accordance with ASTM D7027-13. A conical diamond indenter (120° apex angle, 50 μm tip radius) is used to apply a linearly increasing load of 0.1-20 N to the material surface at a scratching speed of 1 mm / s. The critical load (Lc) and scratch depth are recorded, and the scratch morphology (such as plastic deformation or crack propagation) is analyzed using an optical microscope. This experiment can quantify the material's ability to resist scratching by sharp objects.

[0105] Reciprocating sliding wear test: Based on the improvement of ASTM G65-16 (2021) dry sand / rubber wheel wear test, a ring-block friction and wear tester was used to test the material sample (10×10×5 mm³) against a GCr15 steel grinding ring (HRC 60) under a load of 10 N and a speed of 0.3 m / s for 10 4 After the first cycle, the volume loss rate (mm³ / N·m) was measured by a three-dimensional topography instrument to verify the wear resistance improvement effect.

[0106] Chemical corrosion resistance test: According to ASTM D543-14, material specimens (50 × 25 × 3 mm³) were immersed in 5% HCl, 10% NaOH, and xylene solutions (25°C / 72 h), respectively. The mass change (ΔW%) and tensile strength retention were measured.

[0107] The properties of the nylon materials of Examples 1 to 4 and Comparative Examples 1 to 11 are summarized in Table 1.

[0108] Table 1 Summary of properties of nylon materials in Examples 1 to 4 and Comparative Examples 1 to 11

[0109]

[0110] As can be seen from Table 1, the lack of surface modification leads to a decrease in the interfacial bonding strength between the filler and the nylon matrix, significantly reducing the material's load-bearing capacity and wear resistance. The lack of a calcium fluoride layer or its uneven deposition will weaken the chemically inert barrier effect, reducing the material's corrosion resistance and mechanical stability. When the whisker structure is incomplete or the whisker growth is insufficient, its reinforcement effect is limited, making it difficult to effectively transfer stress and inhibit crack propagation. Insufficient sintering temperature of the coated boron nitride particles or improper control of the ball-milled particle size will affect lubricity and dispersibility, leading to increased wear. Poor hydrolysis conditions of the coupling agent will reduce the grafting efficiency, thereby affecting the filler dispersion and interfacial compatibility. Although the high rigidity and increased crystallinity of a single nylon matrix enhance chemical resistance, they will sacrifice impact toughness and wear resistance. Insufficient polarity or functional groups of the compatibilizer will weaken interfacial adhesion, resulting in a decrease in the mechanical properties of the composite system. Although a too thin calcium fluoride layer can improve flexibility and local scratch resistance, it cannot effectively block the intrusion of corrosive media, reducing the overall chemical resistance.

[0111] 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 transformations made within the scope of the present invention using the contents of the present invention's description and drawings should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-performance scratch-resistant, wear-resistant, and corrosion-resistant nylon material made of plastic instead of steel, characterized by: The composition comprises the following components in parts by weight: 5.0-15.0 parts of surface-modified calcium fluoride@alumina whisker filler, 3.5-8.0 parts of polytetrafluoroethylene-coated boron nitride particles, 50.0-90.0 parts of nylon matrix resin, 1.0-3.0 parts of compatibilizer, 0.1-0.5 parts of antioxidant, and 0.4-1.0 parts of lubricant; The surface-modified calcium fluoride@alumina whisker filler is obtained by surface-modifying calcium fluoride@alumina whiskers with 3,3,3-trifluoropropyltrimethoxysilane; The calcium fluoride@aluminum oxide whiskers are composed of aluminum oxide whiskers and a calcium fluoride nanolayer supported on the surface of the aluminum oxide whiskers; The polytetrafluoroethylene-coated boron nitride particles are composed of boron nitride particles and a polytetrafluoroethylene coating layer coated on the surface of the boron nitride particles; The alumina whiskers are prepared by reacting at 150-250° C. for 6-24 hours in a high-pressure hydrothermal reactor. The boron nitride particles are prepared by wet ball milling in a planetary ball mill at a ball-to-material ratio of 5:1 to 20:1 and a rotation speed of 200 to 600 rpm, and then centrifugally removing the ball milling medium to retain a boron nitride suspension with a particle size of ≤3 μm. The surface-modified calcium fluoride@aluminum oxide whiskers have an average diameter of 500-4500 nm and an average length of 4.5-7.0 μm; the thickness of the calcium fluoride nanolayer is 80-150 nm; The average diameter of the polytetrafluoroethylene-coated boron nitride particles is 200-800 nm; the thickness of the polytetrafluoroethylene coating is 30-80 nm; The nylon matrix resin is a mixture of PA6 and PA66 in a mass ratio of (60-80): (40-20).

2. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 1, characterized in that: The preparation method of the surface-modified calcium fluoride @ alumina whisker filler is as follows: 100 parts by weight of calcium fluoride @ alumina whisker filler are dispersed in 300 to 500 parts of a mixed solvent of ethanol and water, wherein the weight ratio of ethanol to water is 3:1 to 1:1; after ultrasonic treatment for 10 to 30 minutes until uniform dispersion, 0.5 to 3 parts of 3,3,3-trifluoropropyltrimethoxysilane coupling agent is added; the mixture is stirred at 50 to 90° C. and a stirring rate of 200 to 500 rpm for 3 to 8 hours; the solid and liquid phases are then separated by a vacuum filtration device; the solid phase is retained and washed with ethanol 3 to 5 times to remove unreacted coupling agent; and the product is finally dried in an oven at 80 to 120° C. for 2 to 4 hours to obtain the surface-modified calcium fluoride @ alumina whisker filler.

3. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 1, characterized in that: The preparation method of the calcium fluoride @ alumina whisker is as follows: 100 parts by weight of alumina whisker are dispersed in 200-500 parts of deionized water, ultrasonically treated for 10-60 minutes to form a uniform suspension, 5-20 parts of calcium chloride and 3-15 parts of an aqueous solution of ammonium fluoride with a concentration of 0.1-1.5 mol / L are sequentially added under continuous stirring at a stirring rate of 200-800 rpm, the pH is adjusted to 8-11, and an in-situ crystallization precipitation reaction is carried out at 50-80°C for 60-180 minutes. After the reaction is completed, the mixture is washed with deionized water 3-5 times and vacuum filtered to remove soluble byproducts and unreacted ions. The solid phase is retained and dried at 80-120°C for 2-6 hours to obtain a calcium fluoride @ alumina whisker composite powder.

4. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 2, characterized in that: The preparation method of the aluminum oxide whiskers comprises the following steps: dissolving 5 to 20 parts of aluminum nitrate in 50 to 200 parts of deionized water to form an aluminum salt solution, adding 3 to 8 parts of polyethylene glycol and mixing the mixture uniformly at a stirring rate of 200 to 800 rpm, slowly adding 3 to 15 parts of 5 wt.% ammonia water to adjust the pH of the solution to 8 to 12 to form aluminum hydroxide colloid, transferring the mixed solution to a high-pressure hydrothermal reactor and reacting it at 150 to 250° C. for 6 to 24 hours, cooling the mixture to 25 to 60° C. after the reaction, separating the liquid phase by vacuum filtration, and washing the solid phase with deionized water for 3 to 5 times to remove residual templates and soluble ions, retaining the solid phase, drying it at 80 to 120° C. for 2 to 6 hours, and then heating it to 600 to 1000° C. at a heating rate of 2 to 10° C. / min in a calcining furnace and calcining it for 2 to 6 hours to obtain the aluminum oxide whiskers.

5. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 1, characterized in that: The preparation method of the polytetrafluoroethylene-coated boron nitride particles is as follows: 100 parts by weight of boron nitride particles are dispersed in 300-800 parts of an aqueous polytetrafluoroethylene dispersion having a solid content of 30-60 wt.%, and then treated with an ultrasonic power of 300-1000 W for 15-90 min to form a uniform suspension system; 2.0-5.0 parts of sodium lauryl sulfate are added as a dispersant and mixed uniformly at a stirring rate of 300-1000 rpm; hydrochloric acid or ammonia water with a concentration of 5-10 wt.% is added dropwise to adjust the pH to 2-5; the temperature is raised to 60-100°C and the reaction is carried out at a constant temperature for 2-4 h to allow polytetrafluoroethylene to be in situ deposited on the particle surface to form a film. After the reaction, the liquid phase and uncoated polytetrafluoroethylene particles are removed by vacuum filtration, and the solid phase is retained and ultrasonically washed with anhydrous ethanol for 3-5 times to remove surfactants and free ions. The product is then transferred to an oven and dried at 100-150°C for 3-12 h to obtain a primary coated powder. The powder is then placed in a tube furnace under nitrogen protection and heated to 320-400°C at a heating rate of 2-10°C / min and sintered for 1-3 h to densify the polytetrafluoroethylene film layer, ultimately obtaining polytetrafluoroethylene-coated boron nitride particles.

6. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 1, characterized in that: The preparation method of the boron nitride particles is as follows: in parts by weight, 100 parts of hexagonal boron nitride raw material powder with an initial particle size of 5 to 20 μm and a purity of ≥99% is mixed with 500 to 2000 parts of zirconia ball milling media with a diameter of 5 mm, and wet ball milling is performed using a planetary ball mill with a ball-to-material ratio of 5:1 to 20:1 and a rotation speed of 200 to 600 rpm, and 100 to 500 parts of deionized water and 2 to 5 parts of polyvinyl pyrrolidone are added to form a slurry with a solid-liquid ratio of 1:1 to 1:5, the ball mill filling rate is controlled to 50 to 70% and the ball milling time is 10 to 20 hours, the temperature is maintained at ≤60°C during the process to avoid damage to the boron nitride structure, and after the ball milling is completed, the ball milling media is removed by centrifugation and the particle size is retained. The boron nitride suspension is prepared, and the suspension is then vacuum dried at 60-100°C for 4-12 hours to remove the dispersion medium. The suspension is then deagglomerated in a jet mill at a pressure of 0.5-1.2 MPa. Finally, the suspension is heated to 800-1200°C at a heating rate of 5-10°C / min in a nitrogen atmosphere and calcined for 1-2 hours to obtain boron nitride particles.

7. The high-performance scratch-resistant, wear-resistant, and corrosion-resistant plastic-in-steel nylon material according to claim 1, characterized in that: The compatibilizer is polyethylene grafted maleic anhydride; The antioxidant is antioxidant 1010; The lubricant is ethylene bisstearamide.

Images