Surface treatment method for vehicle member, machining method, vehicle member, and vehicle

Abstract

This application relates to the field of vehicle technology and aims to solve the technical problem that the protective film layer of some known vehicle components is difficult to simultaneously improve sealing performance, acid and alkali resistance, and reduce processing costs. It provides a surface treatment method, processing method, vehicle component, and vehicle. The surface treatment method includes: providing a substrate; forming an electrophoretic paint on the surface of the substrate through a first electrophoretic process to obtain an electrophoretic paint material layer, wherein the electrophoretic paint material includes a resin matrix and a conductive material; the conductive material includes conductive carbon black, graphene, and graphite, wherein the mass percentage of the conductive material ranges from 5.5% to 11%, and the mass percentage of the resin matrix ranges from 15% to 20%; and thermosetting the electrophoretic paint material layer to obtain a conductive film layer. The beneficial effects of this application are improved sealing performance and acid and alkali resistance of vehicle components, and reduced processing costs.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to surface treatment methods for vehicle components, vehicle components, and vehicles. Background Technology

[0002] Vehicle components, such as body parts, are prone to corrosion during assembly and painting processes, which can affect subsequent electrophoretic coating. Existing technologies treat these components with various surface treatments to form protective films. However, some protective films struggle to simultaneously improve sealing performance, acid and alkali resistance, and reduce processing costs. Summary of the Invention

[0003] This application provides a surface treatment method, a processing method, a vehicle component, and a vehicle, to solve the technical problem that the protective film layer of some known vehicle components is difficult to simultaneously improve sealing performance, acid and alkali resistance, and reduce processing costs.

[0004] The embodiments of this application are implemented as follows: In a first aspect, this application provides a surface treatment method for a vehicle component, comprising: providing a substrate; providing a conductive material, a resin matrix, and a dispersant to generate an electrophoretic paint, wherein the mass percentage of the resin matrix ranges from 15% to 20%, the mass percentage of the conductive material ranges from 5.5% to 11%, and the conductive material includes conductive carbon black, graphene, and graphite; forming the electrophoretic paint on the surface of the substrate through a first electrophoretic process to obtain an electrophoretic paint material layer; and thermally curing the electrophoretic paint material layer to obtain a conductive film layer.

[0005] According to the surface treatment method for vehicle components in this embodiment, the conductive film layer after thermosetting has strong acid and alkali resistance and corrosion resistance, and can completely and stably seal the substrate to improve the anti-corrosion performance of the substrate, enabling the vehicle components to meet automotive-grade anti-corrosion requirements; and can prevent the risk of ion (such as magnesium ions) accumulation and damage to the stability of the bath solution in subsequent painting processes, so that the subsequent painting processes of vehicle components can be carried out simultaneously with known aluminum die-cast parts and steel / aluminum stamped parts, reducing production costs.

[0006] Meanwhile, even if vehicle components are bumped or scratched during subsequent assembly, the conductive film layer's conductivity allows for a secondary electrophoretic treatment during the painting process, reliably repairing any defects in the conductive film layer. The conductivity of the conductive film layer raises the potential of the vehicle component to the neutral region, fundamentally eliminating the potential difference with steel / aluminum parts and achieving electrochemical assimilation. During subsequent assembly, when vehicle components overlap with other known irregularly shaped metal parts, the risk of galvanic corrosion is significantly reduced, significantly extending the service life of the vehicle components. Applying the conductive film layer via electrophoresis significantly reduces costs and is applicable to the surface treatment of complex vehicle components, exhibiting broad versatility. For example, the cost of the electrophoresis process in this embodiment is approximately 2 to 3 yuan per square meter, far lower than the cost of other known surface treatment solutions.

[0007] Furthermore, in this embodiment, the conductive carbon black has a chain-like structure, enabling the efficient construction of a basic conductive chain network through efficient overlapping. The conductive carbon black also has a low percolation threshold, allowing the surface resistance of the conductive film to rapidly decrease to 10^7–10^8 Ω / □, thereby improving the substrate potential to -0.15V to +0.05V and enhancing the reliability of galvanic corrosion elimination. Graphene possesses high conductivity and an even lower percolation threshold (compared to conductive carbon black). As a two-dimensional sheet structure, graphene can act as a conductive reinforcing agent, bridging carbon black aggregates to form a three-dimensional conductive network with sequentially connected points, lines, and surfaces. This further reduces the resistivity of the conductive film (by approximately 30% or more), improves the electrochemical uniformity of the conductive film, reduces the likelihood of localized micro-regions becoming anodes, inhibits pitting corrosion initiation, and ensures the reliability of the conductive film. Graphite possesses good lubricity, and its micron-sized sheet-like structure can form conductive islands. This not only provides conductivity but also improves the internal stress of the conductive film, enhancing the dispersion stability of conductive materials such as conductive carbon black and graphene. This reduces the risk of cracking under internal stress, preventing the risk of conductive network interruption due to mechanical damage and ensuring the subsequent defect repair capability of the conductive film. Therefore, using conductive materials composed of conductive carbon black, graphene, and graphite can simultaneously improve the conductivity, mechanical properties, and corrosion resistance of the conductive film.

[0008] Furthermore, this embodiment achieves a complete and stable sealing effect on the substrate during the coating process. Other known methods for forming conductive films exist; for example, dip coating requires a thick coating layer and is prone to defects such as sagging and irreparable secondary damage. Powder electrostatic spraying provides good coverage for simple workpieces, but may leave blind spots when coating irregularly shaped parts, failing to completely solve the problem of protecting collinear substrates. While conventional electrophoretic protection methods can seal the substrate, damage to the substrate during subsequent transport or welding assembly cannot be repaired, leading to substrate corrosion. By curing the electrophoretic paint layer, film formation can be achieved, and during the forming process, the conductive material is promoted to form a conductive network, reducing the resistivity of the conductive film.

[0009] In one possible implementation: The conductive material has a mass percentage range of 5.5% to 11%, the conductive carbon black has a mass percentage range of 3% to 5%, the graphene has a mass percentage range of 0.5% to 2%, and the graphite has a mass percentage range of 2% to 4%.

[0010] In one possible implementation: The resin matrix includes at least one of epoxy resin and epoxy-acrylic emulsion.

[0011] In one possible implementation: The preparation steps of the electrophoretic paint include: mixing the conductive material, the resin matrix and the dispersant to obtain a mixture; subjecting the mixture to shear dispersion treatment, ball milling or sand milling dispersion treatment in sequence; the conductivity of the mixture is between 1.0 mS / cm and 1.5 mS / cm; and aging the mixture to obtain the electrophoretic paint.

[0012] In one possible implementation: The step of thermosetting the electrophoretic paint material layer to obtain a conductive film layer includes: heating the electrophoretic paint material layer at a first preset temperature for a first preset time; heating the electrophoretic paint material layer at a second preset temperature for a second preset time, wherein the second preset temperature is greater than the first preset temperature and the second preset time is greater than the first preset time.

[0013] In one possible implementation: The surface resistivity of the conductive film layer ranges from 10^6 Ω / □ to 10^9 Ω / □.

[0014] Secondly, this application provides a method for processing a vehicle component, comprising: providing a vehicle component, wherein the vehicle component is a vehicle component obtained by the aforementioned surface treatment method for vehicle components; performing splicing processing on the vehicle component, wherein the splicing processing includes welding and fastening connection; and performing painting processing on the vehicle component, wherein the painting processing steps include: degreasing treatment, phosphating or zirconium treatment, and a second electrophoretic process.

[0015] Thirdly, this application provides a vehicle component, which is formed by the aforementioned surface treatment method for vehicle components. The vehicle component includes a substrate and a conductive film layer, wherein the conductive film layer covers the surface of the substrate.

[0016] In one possible implementation: The thickness of the conductive film layer ranges from 1 micrometer to 10 micrometers.

[0017] Fourthly, this application provides a vehicle including the aforementioned vehicle components. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a surface treatment method for a vehicle component according to an embodiment of this application.

[0020] Figure 2 This is a structural schematic diagram of a vehicle component according to an embodiment of this application.

[0021] Figure 3 This is a flowchart illustrating a method for processing a vehicle component according to an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the structure of a vehicle according to an embodiment of this application.

[0023] Explanation of key component symbols: 100 vehicle components 10 Substrate 20 conductive film layers 200 vehicles The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. When a component is said to be "set on" another component, it can be directly set on the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Some embodiments of this application are described in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] In known technologies, aluminum die-cast parts and steel / aluminum stamped parts for vehicles can be directly processed into splicing and painting processes without surface treatment, enabling the processing of aluminum die-cast parts and steel / aluminum stamped parts to be carried out on the same production line in the painting workshop.

[0029] In known technologies, interior parts, powertrain components, battery trays, and other battery casings in vehicles are increasingly using materials with low corrosion resistance, such as magnesium alloys. The corrosion defects of these materials are manifested in the following ways: 1. Microgalvanic corrosion: The second phase in the alloy (such as Mg17Al12) forms a potential difference with the magnesium matrix, accelerating localized corrosion (especially in chloride ion environments); 2. Impurity sensitivity: When the content of impurities such as iron (Fe), nickel (Ni), and copper (Cu) exceeds 50 ppm, corrosion resistance decreases significantly.

[0030] Therefore, directly replacing aluminum alloys with materials with poor corrosion resistance, such as magnesium alloys, in one-piece die casting for car bodies will cause the acid and alkali bath solutions used in the pre-painting treatment to corrode the die-cast magnesium parts substrate.

[0031] To address the aforementioned issues, known technologies typically involve surface passivation, physical isolation, or coating with chemical conversion films, anodizing, and micro-arc oxidation for magnesium alloy press-fit parts. However, chemical conversion films suffer from thin layers, low coverage, and poor chemical stability, resulting in poor sealing and stability as a sealing layer for magnesium alloy parts. For instance, using phosphate films as a sealing process for magnesium alloy parts, magnesium ion accumulation in the phosphate coating bath exceeds 150 ppm, causing the appearance and weight of the phosphate film on the car body steel sheet to fail to meet automotive phosphate film standards. Anodized magnesium alloy films also exhibit poor acid and alkali resistance and are expensive. While micro-arc oxidation films offer some acid and alkali resistance, their cost is even higher.

[0032] Furthermore, even if passivation and sealing films are formed on the surface of materials such as magnesium alloys using methods such as chemical conversion coatings, galvanic corrosion is still likely to occur when magnesium alloys and other materials overlap with irregularly shaped metals during subsequent vehicle body assembly, affecting the lifespan of the vehicle body.

[0033] Therefore, in known technologies, it is difficult for protective films to simultaneously improve sealing performance, acid and alkali resistance, and reduce processing costs.

[0034] To address the problem of excessive corrosion of the substrate of non-corrosion-resistant parts such as magnesium alloys in the body-in-white during pretreatment and electrophoresis processes in the painting workshop, this application proposes a surface treatment method for vehicle components that can stably and reliably achieve sealing treatment of non-corrosion-resistant vehicle components.

[0035] See Figure 1 and Figure 2 This embodiment provides a surface treatment method for a vehicle component 100, which includes a substrate 10. The substrate 10 may be a magnesium alloy. The surface treatment method includes: S101, providing the substrate 10; S102, providing a conductive material, a resin matrix, and a dispersant to generate an electrophoretic paint, wherein the mass percentage of the resin matrix ranges from 15% to 20%, and the mass percentage of the conductive material ranges from 5.5% to 11%, and the conductive material includes conductive carbon black, graphene, and graphite; S103, forming the electrophoretic paint on the surface of the substrate 10 through a first electrophoretic process to obtain an electrophoretic paint material layer; S104, thermosetting the electrophoretic paint material layer to obtain a conductive film layer 20.

[0036] According to the surface treatment method for vehicle components in this embodiment, the thermosetting conductive film layer 20 has strong acid and alkali resistance and corrosion resistance, which can completely and stably seal the substrate 10 to improve the corrosion resistance of the substrate 10 and enable the vehicle component 100 to meet automotive-grade corrosion resistance requirements; and it can prevent the accumulation of ions (such as magnesium ions) in subsequent painting processes and the risk of damaging the stability of the bath solution, so that the subsequent painting process of the vehicle component 100 can be carried out simultaneously with known aluminum die-cast parts and steel / aluminum stamped parts, reducing production costs.

[0037] Meanwhile, even if the vehicle component 100 is bumped or scratched during subsequent assembly, the conductive film layer 20, being conductive, allows for a secondary electrophoretic treatment during the painting process to reliably repair defects in the conductive film layer 20. The conductivity of the conductive film layer 20 raises the potential of the vehicle component 100 to the neutral region, fundamentally eliminating the potential difference with steel / aluminum parts and achieving electrochemical assimilation. During subsequent assembly, when the vehicle component 100 overlaps with other known irregularly shaped metal parts, the risk of galvanic corrosion is significantly reduced, significantly extending the service life of the vehicle component 100. Applying the conductive film layer 20 via electrophoresis significantly reduces costs and is applicable to the surface treatment of complex vehicle components 100, exhibiting broad versatility. For example, the cost of the electrophoresis process in this embodiment is approximately 2 to 3 yuan per square meter, far lower than the cost of other known surface treatment solutions.

[0038] Furthermore, in this embodiment, the conductive carbon black has a chain-like structure, enabling the construction of a basic conductive chain network through efficient overlapping. The conductive carbon black also has a low percolation threshold, allowing the surface resistance of the conductive film layer 20 to rapidly decrease to 10^7-10^8 Ω / □, thereby improving the potential of the substrate 10 to -0.15V to +0.05V and enhancing the reliability of eliminating galvanic corrosion. Graphene possesses high conductivity and an even lower percolation threshold (compared to conductive carbon black). As a two-dimensional sheet structure, graphene can act as a conductive reinforcing agent, bridging carbon black aggregates to form a three-dimensional conductive network with sequentially connected points, lines, and surfaces. This further reduces the resistivity of the conductive film layer 20 (by approximately 30% or more), improves the electrochemical uniformity of the conductive film layer 20, reduces the likelihood of localized micro-regions becoming anodes in the conductive film layer 20, inhibits pitting corrosion initiation, and ensures the reliability of the conductive film layer 20. Graphite possesses good lubricity, and its micron-sized sheet-like structure can form conductive islands. This not only provides conductivity but also improves the internal stress of the conductive film layer 20, enhancing the dispersion stability of conductive materials such as conductive carbon black and graphene. This reduces the risk of cracking in the conductive film layer 20 under internal stress, preventing the risk of conductive network interruption due to mechanical damage and ensuring the subsequent defect repair capability of the conductive film layer 20. Therefore, using a conductive material composed of conductive carbon black, graphene, and a mixture of graphite can simultaneously improve the conductivity, mechanical properties, and corrosion resistance of the conductive film layer 20.

[0039] Furthermore, this embodiment achieves a complete and stable sealing effect on the substrate 10 during the coating process. Other known methods for forming the conductive film layer 20 exist. For example, dip coating requires a thick coating process, which is prone to defects such as sagging and irreparable secondary damage. Powder electrostatic spraying provides good coverage for simple workpieces, but may leave blind spots when coating irregularly shaped parts, failing to completely solve the problem of protecting the collinear substrate 10. While conventional electrophoretic protection methods can seal the substrate 10, damage to the substrate 10 during subsequent transportation or welding assembly cannot be repaired, leading to corrosion. By curing the electrophoretic paint layer, the film layer can be formed, and during the forming process, the conductive material is promoted to form a conductive network, reducing the resistivity of the conductive film layer 20.

[0040] Furthermore, when the mass percentage of conductive material is below 5.5%, the conductivity of the conductive film layer 20 is unsatisfactory, and uneven film application occurs in the subsequent secondary electrophoresis step. When the mass percentage of conductive material is above 11%, the conductive material exhibits excessive oil absorption and is prone to uneven dispersion, leading to agglomeration of the conductive material in the resin matrix and poor continuity. When the mass percentage of resin matrix is ​​below 15%, the resin matrix has poor coating properties for the conductive material, resulting in poor storage stability of the pigment paste and easy precipitation, thus reducing the conductivity of the conductive film layer 20. When the mass percentage of resin matrix is ​​below 15%, the conductivity of the electrophoretic paint decreases.

[0041] Therefore, in this embodiment, the mass percentage of the conductive material ranges from 5.5% to 11%, and the mass percentage of the resin matrix ranges from 15% to 20%. This ensures the continuity of the conductive material within the resin matrix and reduces the risk of conductive material precipitation, thereby ensuring the conductivity of the conductive film layer 20. The specific mass percentage of the conductive material can be any value or range from 5.5%, 6%, 7%, 8%, 9%, 10%, and 11%, and this application is not limited to this. Similarly, the specific mass percentage of the resin matrix can be any value or range from 15%, 16%, 17%, 18%, 19%, and 20%, and this application is not limited to this.

[0042] Table 1 presents the test data for the vehicle component 100 in each embodiment. In each embodiment, except for the different mass percentages of conductive carbon black, graphene, graphite, and resin matrix in the conductive material, other dimensional parameters and material parameters of the substrate 10 are the same. Among these, parameters such as self-corrosion potential, phosphating penetration rate, internal stress, scribing corrosion, and film thickness are also included.

[0043] Table 1 As can be seen from the data in Examples 1 to 5 in Table 1, when the mass ratio of conductive material is between 5.5% and 11%, the conductive film layer 20 has a high self-corrosion potential and a phosphating transmittance of over 60%. No filamentary corrosion occurs in the scribing corrosion test, and this is beneficial for increasing the film thickness of the secondary electrophoresis, ensuring the overall film thickness of the coating on the surface of the vehicle component 100. Therefore, setting the mass ratio of conductive material between 5.5% and 11% can balance ensuring the self-corrosion potential, phosphating transmittance, scribing corrosion parameters, and increasing the subsequent coating thickness. When the mass ratio of conductive material is less than 5.5%, the conductivity of the conductive film layer 20 decreases, causing a decrease in its phosphating transmittance, and resulting in a thinner subsequent coating thickness. When the mass ratio of conductive material is greater than 11%, the conductivity of the conductive film layer 20 is too high. Although the phosphating transmittance is high, filamentary corrosion easily occurs during scribing corrosion, with corrosion lines reaching a width of 2 mm.

[0044] As can be seen from the data in Examples 6 to 10 of Table 1, when the mass ratio of the resin matrix is ​​between 15% and 20%, the conductive film layer 20 has a relatively high self-corrosion potential and a phosphating penetration rate of over 60%. No filamentary corrosion was observed in the scribing corrosion test, and this is beneficial for increasing the film thickness of the secondary electrophoresis, thus ensuring the overall film thickness of the coating on the surface of the vehicle component 100. Therefore, setting the mass ratio of conductive material between 5.5% and 11% can balance ensuring the self-corrosion potential, phosphating penetration rate, scribing corrosion parameters, and improving the subsequent coating thickness.

[0045] When the resin matrix content is less than 15%, the conductivity of the conductive film layer 20 increases due to the reduced resin matrix content, leading to a decrease in self-corrosion potential and making the conductive film layer 20 more susceptible to scratch corrosion. When the resin matrix content increases to 20% or more, the conductivity of the conductive film layer 20 decreases due to the increased resin matrix content, resulting in a decrease in phosphating transmittance and hindering the improvement of the thickness of the subsequent secondary electrophoretic coating.

[0046] Table 2 As can be seen from the data of the various embodiments in Table 2, when the mass ratio of the resin matrix is ​​between 15% and 20%, and when the solid content of the resin matrix is ​​constant, the higher the mass ratio of the resin matrix, the higher the internal stress of the conductive film layer 20. When the mass ratio of the resin matrix is ​​constant, the higher the solid content of the resin matrix, the higher the internal stress of the conductive film layer 20.

[0047] In some embodiments, the mass percentage of conductive carbon black ranges from 3% to 5%, the mass percentage of graphene ranges from 0.5% to 2%, and the mass percentage of graphite ranges from 2% to 4%. The specific mass percentage of conductive carbon black can be any value or range from 3%, 3.5%, 4%, 4.5%, and 5%, and this application is not limited to this. The specific mass percentage of graphene can be any value or range from 0.5%, 1%, 1.5%, and 2%, and this application is not limited to this. The specific mass percentage of graphite can be any value or range from 2%, 2.5%, 3%, 3.5%, and 4%, and this application is not limited to this.

[0048] Table 3 As can be seen from the data in Examples 19 to 23 in Table 3, when the mass of graphene and graphite is constant, if the mass ratio of conductive carbon black is too low, the conductivity of the conductive film layer 20 will be insufficient, which will cause the phosphating penetration rate to be less than 60%. If the mass ratio of conductive carbon black is too high, the conductivity of the conductive film layer 20 will be too high, which will easily lead to a decrease in self-corrosion potential and easily cause scribing corrosion.

[0049] As can be seen from the data in Examples 24 to 28 of Table 3, when the mass of conductive carbon black and graphite is constant, if the mass ratio of graphene is too low, the conductivity of the conductive film layer 20 will be insufficient, which will cause the phosphating penetration rate to be less than 60%. If the mass ratio of graphene is too high, the conductivity of the conductive film layer 20 will be too high, which will easily lead to a decrease in self-corrosion potential and easily cause scribing corrosion.

[0050] As can be seen from the data in Examples 29 to 33 in Table 3, when the mass of conductive carbon black and graphene is constant, if the mass ratio of graphite is too low, the conductivity of the conductive film layer 20 will be insufficient, which will cause the phosphating penetration rate to be less than 60%. If the mass ratio of graphite is too high, the conductivity of the conductive film layer 20 will be too high, which will easily lead to a decrease in self-corrosion potential and easily cause scribing corrosion.

[0051] In some embodiments, the resin matrix includes at least one of epoxy resin and epoxy-acrylic emulsion. Epoxy resin and epoxy-acrylic emulsion have good toughness, can accommodate more conductive material, thereby increasing the mass percentage of conductive material and simultaneously reducing the internal stress of the conductive film layer 20.

[0052] In some embodiments, the preparation steps of the electrophoretic paint include: mixing conductive materials, resin matrix and dispersant to obtain a mixture; subjecting the mixture to shear dispersion treatment, ball milling or sand milling dispersion treatment in sequence; the conductivity of the mixture is between 1.0 mS / cm and 1.5 mS / cm; and aging the mixture to obtain the electrophoretic paint.

[0053] Shear dispersion treatment can initially wet and break down large agglomerates in conductive materials and resin matrices. During ball milling or sand milling dispersion treatment, the impact and shear force of the grinding media ensure thorough dispersion of graphene, conductive carbon black, and graphite. Dispersants can adsorb onto the surface of conductive materials and prevent re-agglomeration of conductive materials through steric hindrance mechanisms. In addition, during shear dispersion, resin matrices can adsorb onto the surface of conductive materials and form a resin shell. Curing treatment of the mixture enables it to reach electrochemical equilibrium, resulting in a stable electrophoretic paint.

[0054] Optionally, the dispersant can be a nonionic or anionic polyurethane, acrylic copolymer, etc. The dispersant can be compatible with the resin matrix, thereby improving the dispersion effect of the conductive material within the resin matrix and reducing the risk of agglomeration of the conductive material.

[0055] In the preparation of electrophoretic paint, deionized water or a small amount of co-solvent can be added to make the conductivity of the electrophoretic paint reach the normal electrophoretic range of 1.0 mS / cm - 1.5 mS / cm, so as to ensure the smooth progress of the electrophoresis step.

[0056] In this way, conductive materials can be dispersed and stabilized at the nanoscale in an aqueous system with a resin matrix, preventing agglomeration and sedimentation of the conductive materials.

[0057] In some embodiments, the electrophoresis voltage of the first electrophoresis process ranges from 100V to 350V, and the electrophoresis time ranges from 1 minute to 3 minutes. The pH value of the electrophoretic paint is between 5.2 and 5.6. By combining different electrophoresis voltages and times, the thickness of the conductive film layer 20 can be effectively controlled to ensure the continuity of the conductive network of the conductive film layer 20. The electrophoresis voltage can specifically be any value or any range of values ​​from 100V, 120V, 140V, 160V, 180V, 200V, 220V, 240V, 260V, 280V, 300V, 320V, 340V, and 350V, and is not limited thereto in this application. The electrophoresis time can specifically be any value or any range of values ​​from 1 minute, 2 minutes, and 3 minutes, and is not limited thereto in this application.

[0058] In addition, since conductive materials reduce the insulation of the electrophoretic paint layer, excessively high electrophoretic voltage can easily lead to breakdown problems. Therefore, it is necessary to control the electrophoretic voltage to be less than 350V.

[0059] In some embodiments, the step of obtaining the conductive film layer 20 from the thermosetting electrophoretic paint material layer includes: heating the electrophoretic paint material layer at a first preset temperature for a first preset time; and heating the electrophoretic paint material layer at a second preset temperature for a second preset time, wherein the second preset temperature is greater than the first preset temperature and the second preset time is greater than the first preset time.

[0060] Heating the electrophoretic paint layer at a first preset temperature allows the solvent and moisture in the paint layer to slowly escape, preventing excessive porosity in the paint film. Heating the electrophoretic paint layer at a second preset temperature allows the resin matrix to fully cross-link. The flow and cross-linking shrinkage of the resin matrix can compress the conductive material, causing the conductive material particles to approach each other, thereby forming a conductive network and improving the conductivity of the conductive film layer 20.

[0061] The first preset temperature is between 90℃ and 110℃, and the first preset duration is between 10 minutes and 15 minutes. Specifically, the first preset temperature can be any value or any range of values ​​from 90℃, 95℃, 100℃, 105℃, and 110℃, and this application is not limited to this. Similarly, the first preset temperature can be any value or any range of values ​​from 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, and 15 minutes, and this application is not limited to this.

[0062] The second preset temperature is between 170℃ and 180℃, and the first preset duration is between 20 minutes and 30 minutes. The first preset temperature can specifically be any value or any range of values ​​from 170℃, 172℃, 173℃, 174℃, 175℃, 176℃, 177℃, 178℃, 179℃, and 180℃, and this application is not limited to this. The first preset temperature can specifically be any value or any range of values ​​from 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes, 25 minutes, 26 minutes, 27 minutes, 28 minutes, 29 minutes, and 30 minutes, and this application is not limited to this.

[0063] In some embodiments, the surface resistivity of the conductive film layer 20 ranges from 10^6 Ω / □ to 10^9 Ω / □. Specifically, the surface resistivity can be any value or any range of values ​​among 10^6 Ω / □, 10^7 Ω / □, 10^8 Ω / □, and 10^9 Ω / □, and this application is not limited thereto.

[0064] In some embodiments, prior to the first electrophoresis process, the surface treatment method for the vehicle component further includes: pretreatment of the substrate 10. The pretreatment steps sequentially include ultrasonic degreasing, several industrial water washes, acid etching, several industrial water washes, ultrasonic dust removal, several industrial water washes, phosphating treatment, industrial water washes, and pure water washes.

[0065] The ultrasonic degreasing step creates a clean and highly active surface on the substrate 10, ensuring that subsequent conversion treatments can generate a coating with good adhesion to the substrate 10. When the substrate 10 is a magnesium alloy, a highly alkaline, silicate-free or low-silicate cleaning agent with a pH value greater than 11 can effectively clean the substrate with minimal corrosion damage.

[0066] In the acid etching step, after alkaline cleaning, a proper rinsing should be performed, followed by acid etching to neutralize and remove oxide or hydroxide layers, keeping the etching loss within the specified range. For magnesium alloys, the etching process is based on strongly diluted inorganic and organic acids. Unlike aluminum alloys, fluorides are not necessarily required in the etching bath.

[0067] The ultrasonic cleaning process can remove acid etching residues from the surface of the substrate 10.

[0068] This improves the surface cleanliness of the substrate 10, thereby ensuring the formation quality of the conductive film layer 20.

[0069] In some embodiments, the pretreatment steps sequentially include ultrasonic degreasing, several industrial water washes, acid etching, several industrial water washes, ultrasonic dust removal, several pure water washes, zirconium-based / titanium-based treatment, and several pure water washes.

[0070] In some embodiments, prior to the step of obtaining the conductive film layer 20 from the thermosetting electrophoretic paint material layer, the surface treatment method for the vehicle component further includes several electrophoretic ultrafiltration washes and pure water washes.

[0071] See Figure 3 This application also provides a method for processing a vehicle component, comprising: S201, providing a vehicle component 100, wherein the vehicle component 100 is obtained by any of the aforementioned surface treatment methods for vehicle components; S202, performing a splicing process on the vehicle component 100, the splicing process including welding and fastening; S203, performing a coating process on the vehicle component 100, the coating process steps including: degreasing, phosphating or zirconium treatment, and a second electrophoretic process. Thus, even if scratches or other problems occur on the surface of the vehicle component 100 during the splicing process, a film layer can still be formed again in the second electrophoretic process in step S203, thereby achieving a reliable sealing effect.

[0072] See Figure 1This application also provides a vehicle component 100, which is formed by the aforementioned surface treatment method for vehicle components. The vehicle component 100 includes a substrate 10 and a conductive film layer 20, the conductive film layer 20 covering the surface of the substrate 10. Because this vehicle component 100 is manufactured using the surface treatment method for vehicle components of any of the above embodiments, it possesses the beneficial effects of the surface treatment method for vehicle components of any of the above embodiments, which will not be elaborated further here.

[0073] In some embodiments, the thickness of the conductive film layer 20 ranges from 1 micrometer to 10 micrometers. Specifically, the thickness of the conductive film layer 20 can be any value or any range of values ​​from 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, to 10 micrometers, and this application is not limited to this. By controlling the thickness of the conductive film layer 20, a margin can be provided for the thickness of the subsequent secondary electrophoretic coating, thereby effectively controlling the thickness of the final surface film layer of the vehicle component 100 to within 20 micrometers.

[0074] See Figure 4 This application also provides a vehicle 200, including the aforementioned vehicle component 100. The vehicle component 100 can be used in the body-in-white processing of the vehicle 200, or as an interior part (such as a dashboard frame, seat frame, etc.), powertrain component (engine mount, gearbox housing), battery tray, battery housing, and other parts of the vehicle 200.

[0075] Since the vehicle 200 includes the vehicle component 100 of any of the above embodiments, it has the beneficial effects of the vehicle component 100 of any of the above embodiments, which will not be described again here.

[0076] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A surface treatment method for vehicle components, characterized in that, include: Provide base materials; An electrophoretic paint is generated by providing conductive materials, a resin matrix, and a dispersant, wherein the resin matrix comprises 15% to 20% by mass, the conductive material comprises 5.5% to 11% by mass, and the conductive material includes conductive carbon black, graphene, and graphite. The electrophoretic paint is formed on the surface of the substrate by a first electrophoretic process, and an electrophoretic paint material layer is obtained; The electrophoretic paint material layer is thermosetting to obtain a conductive film layer.

2. The surface treatment method for vehicle components according to claim 1, characterized in that: The conductive carbon black has a mass percentage range of 3% to 5%, the graphene has a mass percentage range of 0.5% to 2%, and the graphite has a mass percentage range of 2% to 4%.

3. The surface treatment method for vehicle components according to claim 1, characterized in that: The resin matrix includes at least one of epoxy resin and epoxy-acrylic emulsion.

4. The surface treatment method for vehicle components according to claim 1, characterized in that: The steps for generating the electrophoretic paint include: mixing the conductive material, the resin matrix, and the dispersant to obtain a mixture; subjecting the mixture to shear dispersion treatment, ball milling, or sand milling dispersion treatment in sequence; the conductivity of the mixture is between 1.0 mS / cm and 1.5 mS / cm; and aging the mixture to obtain the electrophoretic paint.

5. The surface treatment method for vehicle components according to claim 1, characterized in that, The step of thermosetting the electrophoretic paint material layer to obtain a conductive film layer includes: The electrophoretic paint material layer is heated at a first preset temperature for a first preset duration; The electrophoretic paint material layer is heated at a second preset temperature for a second preset duration, wherein the second preset temperature is greater than the first preset temperature and the second preset duration is greater than the first preset duration.

6. The surface treatment method for vehicle components according to claim 1, characterized in that: The surface resistivity of the conductive film layer ranges from 10^6 Ω / □ to 10^9 Ω / □.

7. A method for processing a vehicle component, characterized in that, include: A vehicle component is provided, wherein the vehicle component is a vehicle component obtained by the surface treatment method of any one of claims 1 to 6; The vehicle components are spliced ​​together, and the splicing process includes welding and fastening. The vehicle components are coated, and the coating process includes: degreasing, phosphating or zirconium treatment, and a second electrophoretic process.

8. A vehicle component, characterized in that, The vehicle component is prepared by the surface treatment method for vehicle components as described in any one of claims 1 to 6; The vehicle component includes a substrate and a conductive film layer, wherein the conductive film layer covers the surface of the substrate.

9. The vehicle component according to claim 8, characterized in that: The thickness of the conductive film layer ranges from 1 micrometer to 10 micrometers.

10. A vehicle, characterized in that, Includes the vehicle components as described in claim 9.

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