A powder-coated metal material with UV and high temperature resistance

Abstract

The present invention discloses a powder-coated metal material with UV resistance and high temperature resistance, relating to the technical field of powder-coated metal materials. The technical solution comprises: dissolving PVDF to form a solution; preparing a TiFe / Al composite material and modifying its surface; reinforcing and modifying the TiFe / Al composite material with SiO2; surface-modifying BaTiO3 nanoparticles; adding the modified material to an FPE resin solution, mixing, and electrostatically spraying the mixture onto a metal plate, and curing to obtain the UV-resistant and high-temperature-resistant powder-coated metal material. The present invention significantly improves the high-temperature and UV resistance of the TiFe / Al composite material through PVA surface modification and SiO2 reinforcement modification, enhancing the coating's density and mechanical properties. The BaTiO3 nanoparticles are evenly dispersed, absorbing UV light and converting it into heat energy, while the SiO2 provides UV shielding. The PVDF resin and nanoparticles form a composite structure, optimizing the overall performance of the coating.

Description

Technical Field

[0001] The invention relates to the technical field of powder coating metal materials, in particular to a powder coating metal material with ultraviolet resistance and high temperature resistance properties. Background Art

[0002] Surface protection technologies for metal materials play a crucial role in modern industrial applications, especially for metal components exposed to harsh environments such as high temperature, high humidity, and intense UV radiation. To extend the service life of these metal components and prevent corrosion, aging, and changes in physical properties caused by environmental factors, the development of novel coating materials with high heat and UV resistance has become a hot topic of research. Coating technologies are not only widely used in the automotive, electronics, and construction industries, but increasingly stringent environmental regulations are placing higher demands on the durability and functionality of coating materials.

[0003] Traditional coating technologies such as epoxy resin coatings, polyurethane coatings, and ceramic coatings, although they provide protection for metal materials to a certain extent, show obvious limitations as the application environment conditions change, especially under the long-term effects of high temperature and ultraviolet radiation. For example, epoxy resin coatings usually have good adhesion and certain corrosion resistance, but their high temperature resistance is poor and they tend to fade or peel off as the temperature rises, which cannot meet the needs of long-term use under high temperature conditions. Although polyurethane coatings have certain advantages in terms of UV resistance, they are prone to softening and deformation in extremely high temperature environments, resulting in coating failure. Ceramic coatings have strong stability in high temperature environments, but their UV resistance is poor, and the coating is hard and fragile, and is prone to falling off or cracking during use. In addition, the preparation process of these coating materials is usually complicated and costly, and during the construction process, problems such as uneven thickness or insufficient adhesion are prone to occur, affecting the effect and service life of the coating.

[0004] At present, although some studies have attempted to improve the comprehensive performance of coatings by introducing functional additives or adopting composite material technology, existing technologies have not yet solved the problem of balancing the two requirements of high temperature resistance and UV resistance. Many composite coatings use inorganic materials and other materials in combination with polymer materials to improve their temperature resistance and UV shielding effects. However, the dispersibility, stability and durability of these materials still pose great challenges, especially in extreme environments exposed to ultraviolet rays and high temperatures for a long time. Existing composite coatings often find it difficult to maintain long-term stability. More importantly, existing technologies are mostly single performance improvements, and lack comprehensive optimization between different properties, resulting in a limited scope of application of coating materials.

[0005] When solving the dual protection problems of high temperature and UV rays, existing technologies usually strengthen one of the properties, ignoring the synergistic effect between the two. For example, some technologies emphasize the high-temperature tolerance of the coating, but ignore the long-term impact of UV rays on the coating, causing the coating to easily age and fade under UV exposure. Other technologies focus on improving UV resistance, but have poor adaptability to high-temperature environments. The coating often performs poorly at high temperatures, causing the coating to fail quickly. This single technical approach not only makes it difficult for existing materials to be widely used in complex working environments, but also makes it difficult for the performance of coating materials in specific application scenarios to meet user needs.

[0006] Therefore, developing a coating material that has both excellent UV resistance and high-temperature resistance has become an important direction of current technological development. Specifically, this new coating material should have physical and chemical properties that are stable over a long period of time at high temperatures, while also being able to effectively absorb or shield UV radiation, reducing UV damage to the metal surface. In addition, the coating production process should be highly economical and operational to enable its application in industrial production. Solving this technical challenge will not only significantly extend the service life of metal parts, but also provide strong support for the application of coating technology in aerospace, automotive, construction, and other high-performance fields. Summary of the Invention

[0007] In order to achieve the above-mentioned purpose of the invention and address the above-mentioned technical problems, the present invention provides a method for preparing a powder-coated metal material having UV resistance and high temperature resistance, comprising the following steps:

[0008] S1) adding polyvinylidene fluoride (PVDF) to acetone, stirring and heating until completely dissolved to form a uniform solution;

[0009] S2) dissolving sodium titanate (NaTiO3) and iron chloride (FeCl3) in deionized water to form a uniform solution, adding aluminum powder (Al) as an aluminum source, stirring evenly, adding sodium borohydride (NaBH4), continuing to stir and react, then washing, and vacuum drying to form a TiFe / Al composite material;

[0010] S3) adding the TiFe / Al composite material obtained in step S2) to a polyvinyl alcohol (PVA) solution, stirring continuously to allow the PVA to be uniformly adsorbed on the surface of the TiFe / Al particles, and then vacuum drying to remove the solvent to obtain a surface-modified TiFe / Al composite material;

[0011] S4) dissolving silicon dioxide (SiO2) in deionized water and stirring to form a uniform SiO2 suspension, adding the surface-modified TiFe / Al composite material to the SiO2 suspension solution, and performing ultrasonic treatment using an ultrasonic processor to uniformly distribute the SiO2 on the surface of the TiFe / Al particles, followed by vacuum drying to obtain a surface-enhanced modified TiFe / Al composite material; S5) adding BaTiO3 nanoparticles to a polyvinyl alcohol (PVA) solution, continuously stirring, washing, and vacuum drying to obtain surface-modified barium titanate (BaTiO3) nanoparticles;

[0012] S6) adding surface-modified barium titanate (BaTiO3) nanoparticles and surface-enhanced modified TiFe / Al composite materials to the FPE resin solution, uniformly mixing them using a melt-mixing extruder, and evenly coating the mixed solution on the surface of the metal plate by electrostatic spraying. After the coating is completed, the metal plate is placed in an oven for curing to obtain a powder-coated metal material.

[0013] Preferably, in step S1), the mass ratio of polyvinylidene fluoride (PVDF) to acetone is 1:3-1:5.

[0014] Preferably, in step S2), the mass ratio of sodium titanate, iron chloride and deionized water is 1:(1-2):20, the aluminum powder is 5%-10% of the total amount of sodium titanate and iron chloride, and the mass of NaBH4 is 10%-20% of NaTiO3.

[0015] Preferably, the particle size of the aluminum powder in step S2) is 5-10 μm.

[0016] Preferably, in step S3), the mass ratio of the TiFe / Al composite material to the polyvinyl alcohol (PVA) solution is 1:1.

[0017] Preferably, in step S4), the mass ratio of silicon dioxide (SiO2) to deionized water is 1:10-1:20, and the mass ratio of the surface-modified TiFe / Al composite material to SiO2 is 1:1-1:2.

[0018] Preferably, the concentration of the polyvinyl alcohol solution in steps S3) and S5) is 5-10%.

[0019] Preferably, in step S5), the mass ratio of BaTiO3 nanoparticles to PVA solution is 1:5-1:10, and the size of the BaTiO3 nanoparticles is 50-100 nm.

[0020] Preferably, in step S6), the mass ratio of PVDF solution: TiFe / Al composite material: BaTiO3 nanoparticles is 10:1:1-10:2:1.

[0021] Preferably, in step S6), the curing temperature is 150-180° C., and the curing time is 30-60 minutes.

[0022] The present invention also provides a powder coating metal material with UV resistance and high temperature resistance, and the powder coating metal material is prepared by the above preparation method.

[0023] The technical solution provided by the present invention brings beneficial effects:

[0024] The high-temperature resistance is significantly improved. Through PVA surface modification and SiO2 enhancement modification process, the surface defects of TiFe / Al composite materials are reduced, forming a dense coating structure, which effectively suppresses stress concentration in the heat conduction path; at the same time, the high thermal stability of SiO2 and the metal-oxide synergistic effect of TiFe / Al enhance the overall thermomechanical properties of the coating.

[0025] Excellent UV resistance. Surface-modified BaTiO3 nanoparticles are evenly dispersed through PVA adsorption. Their high dielectric constant and piezoelectric properties can absorb UV photons and convert them into heat energy for release. At the same time, the TiFe / Al composite material absorbs UV energy and forms a multi-level protection mechanism with the UV shielding effect of SiO2.

[0026] Enhance the structural density and mechanical properties of the coating. The polar groups (hydroxyl groups) of PVA form hydrogen bonds with the metal oxides on the TiFe / Al surface, enhancing the interfacial bonding strength. SiO2 is evenly coated on the surface of TiFe / Al particles through ultrasonic dispersion, forming a physical barrier, reducing the crack propagation path, and improving the ductility and impact resistance of the coating.

[0027] The synergistic optimization of processes improves overall performance. The high crystallinity of PVDF resin and the rigid nanoparticles of TiFe / Al / BaTiO3 form a "soft-hard" composite structure. Through uniform dispersion in the melt-mixing extruder, uniform stress distribution in the coating is achieved, thus taking into account both flexibility and hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a SEM photograph of Example 1 of the present invention;

[0029] Figure 2 This is a SEM photograph of Comparative Example 1 of the present invention;

[0030] Figure 3 This is a SEM photograph of Comparative Example 2 of the present invention;

[0031] Figure 4 This is a cross-sectional view of the coating and substrate in embodiment 1 of the present invention.

[0032] Figure 5 This is the UV reflectivity test data chart. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the embodiments. Of course, the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Example 1

[0035] Step S1: Dissolving polyvinylidene fluoride (PVDF)

[0036] Polyvinylidene fluoride (PVDF) was added to acetone at a mass ratio of 1:4. The mixture was heated to 80°C under stirring and stirred for 3 hours until the PVDF was completely dissolved to form a uniform solution.

[0037] Step S2: Preparation of TiFe / Al composite material

[0038] Sodium titanate (NaTiO3) and iron chloride (FeCl3) are dissolved in deionized water at a mass ratio of 1:1:20 and stirred evenly. Aluminum powder (Al) is added as an aluminum source. The aluminum powder is 10% of the total amount of sodium titanate and iron chloride and has a size of 5-10 μm. Stirring is continued for 30 minutes to ensure uniform dispersion. Then, sodium borohydride (NaBH4) is added with a mass of 15% of NaTiO3. The stirring reaction is continued for 1 hour. The reaction temperature is maintained at room temperature. After the reaction is completed, the reactant is washed with deionized water 3 times to remove residual solvent and impurities. The washed material is vacuum dried in a vacuum drying oven at 60°C for 24 hours to obtain a TiFe / Al composite material.

[0039] Step S3: Surface modification of TiFe / Al composite material

[0040] The TiFe / Al composite material obtained in step S2 was added to a polyvinyl alcohol (PVA) solution at a mass ratio of 1:1 and a concentration of 10% of the PVA solution. The mixture was stirred for 2 hours to allow the PVA to be uniformly adsorbed on the surface of the TiFe / Al particles. The mixture was vacuum dried at 60° C. for 24 hours, and the solvent was removed to obtain a surface-modified TiFe / Al composite material.

[0041] Step S4: Surface enhancement and modification of TiFe / Al composite material

[0042] Silicon dioxide (SiO2) was added to deionized water at a mass ratio of 1:10 and stirred to prepare a SiO2 suspension. The surface-modified TiFe / Al composite material was added to the SiO2 suspension at a mass ratio of 1:1. The mixture was ultrasonically treated for 30 minutes using an ultrasonic processor to ensure that SiO2 was evenly distributed on the surface of the TiFe / Al particles. The mixture was vacuum dried at 60°C for 24 hours in a vacuum drying oven to obtain a surface-enhanced modified TiFe / Al composite material.

[0043] Step S5: Surface modification of BaTiO3 nanoparticles

[0044] BaTiO3 nanoparticles were added to a 10% PVA solution at a mass ratio of 1:10. The size of the BaTiO3 nanoparticles was 80-100 nm. The mixture was stirred for 1 hour to ensure that the BaTiO3 nanoparticles were fully dispersed. The solution was washed three times with deionized water to remove residual PVA. The washed BaTiO3 nanoparticles were then vacuum dried at 60°C for 24 hours to obtain surface-modified barium titanate (BaTiO3) nanoparticles.

[0045] Step S6: Preparing powder-coated metal material

[0046] Take the surface-enhanced modified TiFe / Al composite material obtained in step S4 and the surface-modified BaTiO3 nanoparticles obtained in step S5, and add the two to a PVDF resin solution. The mass ratio of PVDF solution: surface-enhanced modified TiFe / Al composite material: surface-modified BaTiO3 nanoparticles is 10:2:1. After mixing, use a melt-mixing extruder to evenly mix the mixture. The mixture is evenly coated on the surface of the metal plate by electrostatic spraying. The thickness of the spray layer is controlled to be 100 μm. The coated metal plate is placed in an oven for curing treatment. The curing temperature is set to 180°C and the curing time is 30 minutes to ensure that the coating is evenly cured to obtain a powder-coated metal material with UV resistance and high temperature resistance.

[0047] Example 2

[0048] The preparation was carried out according to the same preparation method as in Example 1, except that the mass ratio of the surface-modified TiFe / Al composite material to SiO2 in step S4) was 1:2.

[0049] Example 3

[0050] The preparation method is the same as that in Example 1, except that the mass ratio of PVDF solution: surface-enhanced modified TiFe / Al composite material: surface-modified BaTiO3 nanoparticles in step S6) is 10:1:1.

[0051] Example 4

[0052] The preparation method is the same as that in Example 1, except that in step S2), the mass ratio of sodium titanate, iron chloride and deionized water is 1:2:20.

[0053] Example 5

[0054] The preparation was carried out according to the same preparation method as in Example 1, except that in step S5), the mass ratio of BaTiO3 nanoparticles to PVA solution was 1:5.

[0055] Example 6

[0056] The preparation method is the same as that in Example 1, except that the aluminum powder in step S2) is 5%-10% of the total amount of sodium titanate and iron chloride.

[0057] Comparative Example 1

[0058] The preparation method is the same as that in Example 1, except that the TiFe / Al composite material and the BaTiO3 nanoparticles are not subjected to PVA adsorption and the surface is not modified.

[0059] Comparative Example 2

[0060] The TiFe / Al composite material was prepared by the same preparation method as in Example 1, except that silicon dioxide was not used for surface enhancement modification.

[0061] Comparative Example 3

[0062] The same preparation method as in Example 1 was used for the preparation, except that BaTiO3 nanoparticles were not added and TiFe / Al composite materials were used instead.

[0063] Comparative Example 4

[0064] The same preparation method as in Example 1 was used for the preparation, except that magnesium powder (Mg) was used instead of aluminum powder.

[0065] Comparative Example 5

[0066] The same preparation method as in Example 1 was used for the preparation, except that zinc powder (Zn) was used instead of aluminum powder.

[0067] Experimental test:

[0068] 1. Conventional performance test

[0069] Standard: "HGT3830-2022 Pre-coated coil coatings".

[0070] 2. Thermal stability analysis

[0071] The thermal decomposition temperature (Td) was measured using a thermogravimetric analyzer (TGA, model TGA2, Mettler Toledo GmbH, Greifensee, Switzerland). The samples for TGA measurement were dried at 90°C for 1 hour and then heat-treated to 800°C at a heating rate of 10°C / min under nitrogen flow.

[0072] 3. Ultraviolet reflectivity

[0073] Test sample preparation: Select a metal plate coated with powder coating; ensure that the coating surface is flat and free of contamination.

[0074] Test method: Place the coated metal plate into the sample chamber of the UV-Vis spectrophotometer, ensuring that the coating faces the light source. Select the reflection mode for measurement and measure the reflectivity of the coating within the wavelength range of 200nm to 400nm.

[0075] 4. UV aging test

[0076] Light source: Select UV-B (280-315nm) UV light source, 35℃, 100h test usually UV-A (315-400nm) or.

[0077] Reflectance change: Use a spectroscopic reflectometer to measure the reflectance change before and after UV exposure. Record the color change.

[0078] Table 1 Conventional performance test data

[0079]

[0080] Examples 1 through 6 of the present invention all performed well across conventional performance indicators, with Example 1 performing particularly well in solvent abrasion resistance, gloss, reverse impact, and cupping tests. This demonstrates that the preparation process of the present invention can effectively improve the overall performance of powder-coated metal materials, particularly with respect to solvent resistance, impact resistance, ductility, and surface gloss. The optimized formulation and process parameters of Example 1 are optimal, meeting high-standard application requirements.

[0081] Table 2 TGA data of samples

[0082] sample T5(℃) T10(℃) T50(℃) 800℃(wt%) Example 1 257.3 277.5 337.8 38.20 Example 2 239.4 264.1 319.6 34.53 Example 3 224.6 244.8 304.7 31.91 Example 4 234.2 254.3 309.5 32.81 Example 5 229.5 249.1 298.6 31.21 Example 6 219.8 239.6 288.3 30.42 Comparative Example 1 194.7 219.8 269.9 24.68 Comparative Example 2 204.5 224.9 279.1 26.78 Comparative Example 3 179.9 209.5 259.6 22.11 Comparative Example 4 184.6 214.3 264.2 23.38 Comparative Example 5 199.2 229.1 274.3 24.32

[0083] Examples 1 to 6 of the present invention are significantly better than Comparative Examples 1 to 5 in terms of thermal decomposition temperature (T5, T10, T50) and residual mass (800°C), indicating that the preparation process of the present invention can significantly improve the thermal stability of the material.

[0084] Example 1 exhibits the best thermal stability, with T5, T10, and T50 temperatures of 257.3°C, 277.5°C, and 337.8°C, respectively, and a high residual mass of 38.20%, significantly higher than the comparative example. Example 1 exhibits the highest residual mass at high temperatures, demonstrating improved durability and a lower thermal decomposition rate in high-temperature environments. The superior performance of Example 1 is closely related to its optimized TiFe / Al composite material ratio, surface modification process, and the introduction of BaTiO3 nanoparticles.

[0085] Figure 1-3 1 is the SEM picture of embodiment, comparative example 1 and comparative example 2. Figure 1 The microstructure is smooth and defect-free. Figure 2 The coating microstructure becomes rough, and some micropores and defects appear in the coating surface. Figure 3 As shown, the surface of the powder coating is also slightly rough, and coating defects have increased. The coating of Example 1 exhibits a smooth and defect-free microstructure, significantly improving UV resistance and high temperature resistance. Comparative Example 1 lacks PVA adsorption and surface modification, resulting in a rough coating structure and defects, leading to performance degradation. Although Comparative Example 2 does not use SiO2 for surface enhancement and modification, its coating structure is slightly improved compared to Comparative Example 1, and its performance is also improved, but still inferior to Example 1.

[0086] Figure 5 It shows that the superiority of Examples 1-6, the enhanced UV stability, through PVA surface modification, SiO2 enhancement treatment and other technical means, in Examples 1-6, the UV absorption capacity and stability of the composite materials are significantly improved, especially in terms of resistance to UV degradation, and are suitable for long-term UV irradiation environment. Improved material durability: In the case of multiple treatments such as Example 4 and Example 6, the UV stability of the material reaches the best, and it shows a low degradation rate during long-term use. The UV stability of the comparative experiment is poor: The materials in the comparative experiments 1-5 generally show weak UV absorption capacity, rapid degradation, poor UV stability, and cannot meet the application requirements in high UV environments.

[0087] Table 3 UV aging test record form

[0088] project Reflectivity change (%) ΔE* ΔL* Δa* Δb* Example 1 -1.2 1.5 -0.5 0.2 0.8 Example 2 -2.5 2.8 -1.0 0.5 1.3 Example 3 -3.1 3.6 -1.3 0.8 1.5 Example 4 -2.8 3.2 -1.1 0.7 1.4 Example 5 -3.5 4.0 -1.5 1.0 1.8 Example 6 -3.0 3.4 -1.2 0.9 1.3 Comparative Example 1 -5.4 6.5 -2.2 1.8 2.5 Comparative Example 2 -4.7 5.6 -2.0 1.6 2.0 Comparative Example 3 -4.5 5.2 -1.9 1.4 2.1 Comparative Example 4 -4.2 5.0 -1.8 1.3 1.9 Comparative Example 5 -4.3 5.1 -1.8 1.3 2.0

[0089] ΔE*: Total color difference, a comprehensive consideration of changes in L*, a*, and b, is the most intuitive parameter for measuring color change. The larger the ΔE value, the more obvious the color change.

[0090] ΔL*: Brightness change, positive value indicates brighter, negative value indicates darker.

[0091] Δa*: The difference between red and green. Positive values ​​indicate a reddish color, while negative values ​​indicate a greenish color.

[0092] Δb*: The difference between yellow and blue. Positive values ​​indicate a yellowish color, while negative values ​​indicate a bluish color.

[0093] Example 1 exhibited the lowest reflectivity change of all samples tested, demonstrating its superior ability to maintain reflective properties. The ΔE value for Example 1 was significantly lower than that of the other examples and the comparative example. This low ΔE* value indicates minimal color change after UV exposure, a critical attribute for outdoor applications and long-term durability.

[0094] Although the reflectivity changes and ΔE* values ​​shown in Examples 2 to 6 are better than those in the comparative example, they are still higher than those in Example 1, which indicates that the material combination and preparation process in Example 1 are more optimized.

[0095] The test data of Comparative Examples 1 to 5 showed significant changes in color and reflectivity, especially Comparative Example 1, which showed that the performance of the material was greatly reduced without PVA adsorption and surface treatment.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a powder-coated metal material having UV resistance and high temperature resistance, comprising the following steps: S1) adding polyvinylidene fluoride (PVDF) to acetone, stirring and heating until completely dissolved to form a uniform solution; S2) dissolving sodium titanate NaTiO3 and iron chloride FeCl3 in deionized water to form a uniform solution, adding aluminum powder (Al) as an aluminum source, stirring uniformly, adding sodium borohydride NaBH4, continuing to stir and react, then washing, and vacuum drying to form a TiFe / Al composite material; S3) adding the TiFe / Al composite material obtained in step S2) to the polyvinyl alcohol (PVA) solution, stirring continuously to allow the PVA to be uniformly adsorbed on the surface of the TiFe / Al particles, and then vacuum drying to remove the solvent to obtain a surface-modified TiFe / Al composite material; S4) dissolving silicon dioxide (SiO2) in deionized water and stirring to form a uniform SiO2 suspension, adding the surface-modified TiFe / Al composite material to the SiO2 suspension solution, and performing ultrasonic treatment using an ultrasonic processor to uniformly distribute the SiO2 on the surface of the TiFe / Al particles, followed by vacuum drying to obtain a surface-enhanced modified TiFe / Al composite material; S5) adding BaTiO3 nanoparticles to a polyvinyl alcohol (PVA) solution, continuously stirring, washing, and vacuum drying to obtain surface-modified barium titanate (BaTiO3) nanoparticles; S6) adding the surface-modified barium titanate BaTiO3 nanoparticles and the surface-enhanced modified TiFe / Al composite material to the PVDF solution of step S1), uniformly mixing them using a melt-mixing extruder, and evenly coating the mixed solution on the surface of the metal plate by electrostatic spraying. After the coating is completed, the metal plate is placed in an oven for curing to obtain a powder-coated metal material.

2. The method for preparing a powder-coated metal material according to claim 1, wherein: In step S1), the mass ratio of polyvinylidene fluoride (PVDF) to acetone is 1:3-1:

5.

3. The method for preparing a powder-coated metal material according to claim 1, wherein: In step S2), the mass ratio of sodium titanate, iron chloride and deionized water is 1:(1-2):20, the aluminum powder accounts for 5%-10% of the total amount of sodium titanate and iron chloride, the mass of NaBH4 accounts for 10%-20% of NaTiO3, and the particle size of the aluminum powder is 5-10 μm.

4. The method for preparing a powder-coated metal material according to claim 1, wherein: In step S3), the mass ratio of the TiFe / Al composite material to the polyvinyl alcohol (PVA) solution is 1:

1.

5. The method for preparing a powder-coated metal material according to claim 1, wherein: In the step S4), the mass ratio of silicon dioxide SiO2 to deionized water is 1:10-1:20, and the mass ratio of the surface-modified TiFe / Al composite material to SiO2 is 1:1-1:

2.

6. The method for preparing a powder-coated metal material according to claim 1, wherein: The concentration of the polyvinyl alcohol solution in steps S3) and S5) is 5-10%.

7. The method for preparing a powder-coated metal material according to claim 1, wherein: Step S5) The mass ratio of BaTiO3 nanoparticles to PVA solution is 1:5-1:10, and the size of the BaTiO3 nanoparticles is 50-100 nm.

8. The method for preparing a powder-coated metal material according to claim 1, wherein: In step S6), the mass ratio of PVDF solution: TiFe / Al composite material: BaTiO3 nanoparticles is 10:1:1-10:2:

1.

9. The method for preparing a powder-coated metal material according to claim 1, wherein: In step S6), the curing temperature is 150-180° C., and the curing time is 30-60 minutes.

10. A powder-coated metal material having UV resistance and high temperature resistance, characterized in that: The powder-coated metal material is prepared by the preparation method according to any one of claims 1 to 9.

Images