Processing method and system of high-corrosion-resistance extinction electrophoresis aluminum profile

Abstract

The invention provides a machining method and system for a high-corrosion-resistance extinction electrophoresis aluminum profile. The machining method comprises the steps that an aluminum alloy base material is subjected to anodic oxidation, and a to-be-treated workpiece with a porous oxidation film is prepared; collecting a workpiece surface transient response potential at high frequency in a preset monitoring time period at the initial stage of electrification, and synchronously obtaining a bath solution system reference equilibrium potential; calculating the numerical deviation degree of the transient response potential and the reference equilibrium potential, and processing to obtain a characteristic difference index representing the pore impedance distribution of the oxide film; converting the characteristic difference index into a voltage compensation factor, multiplying a basic set voltage by the factor to obtain an execution voltage, and performing electrophoretic deposition on the workpiece under the execution voltage; correcting preset curing process parameters, generating a target curing curve containing segmented variable temperature rate and constant temperature duration, and matching the target curing curve with a film layer thermal cross-linking reaction window; and after electrophoresis, cleaning and draining the workpiece, and carrying out thermal cross-linking curing according to a target curing curve to prepare the high-corrosion-resistance extinction electrophoresis aluminum profile.

Description

Technical Field

[0001] This application belongs to the field of processing, and in particular relates to a processing method and system for high corrosion-resistant, matte electrophoretic aluminum profiles. Background Technology

[0002] To improve the corrosion resistance, weather resistance, and aesthetic appeal of aluminum alloy profiles, surface treatment is necessary. The electrophoretic deposition stage of the matte electrophoretic process is controlled by a constant voltage or a preset stepped voltage, while the thermosetting stage follows a fixed heating rate and holding time. However, microscopic segregation of the aluminum substrate, aging of the anodizing bath, or differences in resistance due to contact with tooling fixtures can lead to non-uniformity in the pore structure of the anodic oxide film on the workpiece surface.

[0003] The current processing method lacks a co-control mechanism between the electrophoretic deposition and thermal curing processes. In the process logic, curing parameters are set based on empirical values ​​or paint manufacturer recommendations. However, the actual deposition state of the electrophoretic film affects thermal conductivity and crosslinking kinetics. Existing methods fail to analyze the thermal impedance characteristics of the film based on electrochemical response data during deposition, neglecting the thermal conduction hysteresis phenomenon when films of different thicknesses or densities are heated. Heating workpieces with different thermal conductivity characteristics using curing curves can lead to incomplete crosslinking in some films or resin aging and discoloration in others due to overheating. Therefore, existing electrophoretic processing methods struggle to stably produce matte aluminum profiles with both high appearance quality and high corrosion resistance, necessitating a processing method capable of compensation and synergistic optimization based on process feedback. Summary of the Invention

[0004] This invention proposes a processing method for high corrosion-resistant electrophoretic aluminum profiles, addressing the problem of the lack of a processing method in the prior art capable of compensation and collaborative optimization based on process feedback, comprising: Anodizing is performed on an aluminum alloy substrate to obtain a workpiece with a porous oxide film. The workpiece is then placed in an electrophoresis bath to construct an electrophoresis circuit. During a preset monitoring period at the initial stage of energization, the instantaneous response potential of the workpiece surface is acquired at high frequency, and the reference equilibrium potential of the bath system is obtained. Calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and calculate the characteristic difference index representing the pore impedance distribution of the oxide film based on the numerical deviation; The voltage compensation factor is calculated using the characteristic difference index through a preset compensation algorithm. The basic set voltage is multiplied by the voltage compensation factor to obtain the execution voltage. Electrophoretic deposition is performed on the workpiece under the execution voltage. The amount of charge transfer during the deposition process is monitored simultaneously. The thermal conduction hysteresis coefficient of the deposited film is calculated by combining the value of the execution voltage and the characteristic difference index through a thermal impedance equivalent model. Based on the thermal conduction hysteresis coefficient, the preset curing process parameters are modified to generate a target curing curve that includes segmented temperature change rate and constant temperature duration, matching the thermal crosslinking reaction window of the film layer; the workpiece that has completed electrophoretic deposition is cleaned and drained, and thermal crosslinking curing is performed according to the target curing curve to obtain a high corrosion resistant matting electrophoretic aluminum profile.

[0005] Furthermore, the present invention also relates to a processing system for high corrosion-resistant, matte electrophoretic aluminum profiles, comprising the following modules: The acquisition module is used to perform anodizing treatment on aluminum alloy substrate to obtain a workpiece with a porous oxide film; the workpiece is placed in the electrophoresis tank to construct an electrophoresis circuit, and the instantaneous response potential of the workpiece surface is acquired at high frequency during the preset monitoring period at the beginning of power-on, and the reference equilibrium potential of the tank system is obtained. A construction module is used to calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and to calculate the characteristic difference index representing the pore impedance distribution of the oxide film based on the numerical deviation. The calculation module is used to calculate the voltage compensation factor using the feature difference index through a preset compensation algorithm, multiply the base setting voltage by the voltage compensation factor to obtain the execution voltage, and perform electrophoretic deposition on the workpiece under the execution voltage; simultaneously monitor the amount of charge transfer during the deposition process, and calculate the thermal conduction hysteresis coefficient of the deposited film by combining the value of the execution voltage and the feature difference index through a thermal impedance equivalent model. The execution module is used to modify the preset curing process parameters based on the thermal conduction hysteresis coefficient, generate a target curing curve including segmented temperature change rate and constant temperature duration, and match the thermal crosslinking reaction window of the film layer; clean and drain the workpiece after electrophoretic deposition, and perform thermal crosslinking curing according to the target curing curve to obtain a high corrosion resistant matting electrophoretic aluminum profile.

[0006] This invention utilizes the potential response deviation in the electrophoresis circuit to represent the microscopic impedance distribution of the oxide film pores, and accordingly uses a voltage compensation factor to correct the deposition process, establishing the consistency between the film thickness and the distribution of matte particles. A correlation model from electrochemical deposition characteristics to thermophysical properties is constructed, and by calculating the thermal conductivity hysteresis coefficient of the film, the influence of the deposition state on the heating process is revealed. The resulting curing curve can better match the specific thermal crosslinking reaction window of the film, avoiding insufficient crosslinking or overheating aging caused by general curing processes. This invention improves the corrosion resistance of finished aluminum profiles while ensuring a delicate and soft matte finish on the surface. Attached Figure Description

[0007] Figure 1 A flowchart of the first embodiment; Figure 2This is a schematic diagram of the instantaneous response potential acquisition during the initial stage of power-on. Figure 3 This is a schematic diagram illustrating the mapping relationship between the characteristic difference index and the execution voltage. Figure 4 This is a schematic diagram of the reconstruction of the target curing curve based on thermal hysteresis. Detailed Implementation

[0008] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0009] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0010] In the first embodiment, the present invention proposes a processing method for highly corrosion-resistant, photosensitive aluminum profiles, such as... Figure 1 ,include: S1, perform anodizing on the aluminum alloy substrate to obtain a workpiece with a porous oxide film; place the workpiece into the electrophoresis bath to construct an electrophoresis circuit, and collect the instantaneous response potential of the workpiece surface at high frequency during the preset monitoring period at the beginning of the power-on, and obtain the reference equilibrium potential of the bath system. 6063 aluminum alloy extruded profiles were selected as the substrate and subjected to degreasing, water washing, alkaline etching, water washing, and neutralization brightening treatments in sequence to remove the natural oxide layer and impurities on the surface. The workpiece was then placed in a sulfuric acid electrolyte for anodizing. The sulfuric acid concentration was controlled at 160g to 180g per liter, the aluminum ion concentration was controlled at 5g to 15g per liter, the bath temperature was maintained at 18℃ to 22℃, the current density was set at 1.0A to 1.5A per square decimeter, and the oxidation time was 30 to 40 minutes. This resulted in the growth of an anodized film with a thickness of 10μm to 12μm on the surface of the aluminum substrate. This oxide film has a regularly arranged nanoscale microporous structure. After cleaning, the treated workpiece was obtained.

[0011] The electrophoresis bath solution uses acrylic resin matte electrophoretic paint, with a solid content controlled at 6% to 8%, pH value adjusted to 8.0±0.2, and bath temperature controlled at 20℃ to 24℃. The workpiece is immersed in the bath solution as the anode, and a stainless steel plate is used as the cathode to construct the electrophoresis circuit. The preset monitoring period is set to the first 0.5s to 2s after power-on, and a high-sensitivity voltage sensor is used to collect the instantaneous response potential of the workpiece surface at a sampling frequency of 500Hz to 1000Hz. The reference equilibrium potential is the steady-state potential value measured by a standard test piece under ideal bath conditions, or it is set as the theoretical impedance-free voltage drop value.

[0012] In an optional embodiment, the step of acquiring the instantaneous response potential of the workpiece surface at high frequency during a preset monitoring period at the initial stage of power-on, and obtaining the reference equilibrium potential of the bath system, includes: The preset monitoring period is after power-on. Instant Second; With sampling frequency The voltage values ​​on the workpiece surface are collected at Hz within the preset monitoring period to obtain a voltage sequence set. , where N is the total number of sampling points; Before energizing, the open-circuit potential of the workpiece in the electrophoresis bath is measured using a reference electrode, and this open-circuit potential is defined as the reference equilibrium potential of the bath system. .

[0013] Specifically, the monitoring window during the initial stage of electrophoresis is defined as the period from 0.1 to 0.5 seconds after power-on. This time period is chosen to avoid interference from the instantaneous current surge during power-on, while simultaneously detecting the microscopic electrical response of the oxide film in the initial stage of establishing the electric field. During this period, the data acquisition card performs intensive sampling of the voltage on the workpiece surface relative to the reference electrode at a high frequency of 2000 Hz, acquiring 800 discrete voltage data points within a 0.4-second duration, forming a voltage sequence set that reflects the impedance characteristics of the film layer.

[0014] Furthermore, to establish a benchmark for voltage fluctuations, measurements must be taken under static conditions before applying an external voltage. Operators use a silver / silver chloride reference electrode or a saturated calomel electrode to test the workpiece's natural potential in an unenergized electrophoresis bath. The open-circuit potential reflects the electrochemical equilibrium state between the oxide film on the workpiece surface and the bath solution, and is defined as the benchmark equilibrium potential. For example, the measured value is -0.75V. Figure 2 .

[0015] To construct a porous anodic oxide film with a specific pore structure as a substrate for electrophoretic deposition, in an optional embodiment, the anodizing treatment of the aluminum alloy substrate to obtain a workpiece with a porous oxide film includes: An aluminum alloy substrate was placed as the anode in an electrolyte with a sulfuric acid concentration of 170 g / L. The electrolyte temperature is kept constant at 20℃; The current density is Electrolysis is performed using direct current for 30 minutes; A porous anodic oxide film with a thickness of 12 micrometers is formed on the surface of an aluminum alloy substrate, which is then washed with water and used as the workpiece to be processed.

[0016] An electrolyte solution with a sulfuric acid concentration of 170 g / L was prepared, and the temperature of the solution was strictly maintained at 20°C using a cooling system to control the balance between the dissolution rate and the growth rate of the oxide film. An aluminum alloy substrate was immersed in the solution as the anode and connected to the positive terminal of a DC power supply.

[0017] After the process starts, a constant current density is applied. Electrolytic treatment is performed. During the 30-minute anodizing process, an aluminum oxide film grows in situ on the surface of the aluminum substrate, forming a regular nanoscale porous structure under the assisted dissolution effect of an electric field. This process prepares a porous anodized film with a thickness of approximately 12 micrometers on the substrate surface. After multiple water washes to remove residual acid, a workpiece with high specific surface area and specific insulation properties is obtained.

[0018] S2, calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and calculate the characteristic difference index representing the oxide film pore impedance distribution based on the numerical deviation; The microprocessor receives the collected data and calculates the absolute value of the instantaneous response potential minus the reference equilibrium potential point by point to obtain a series of numerical deviations. Since the potential change at the moment of energization can reflect the microscopic impedance characteristics of the oxide film pores, a time decay function is used to weight the numerical deviations, that is, the closer the data is to the energization start point, the greater the weight. The weighted deviation values ​​are integrated or accumulated to obtain the characteristic difference index. The larger the index value, the greater the difference between the oxide film pore impedance on the workpiece surface and the standard state, which may indicate pore blockage or excessive film thickness.

[0019] To transform the massive amounts of collected voltage data into a single index for evaluating the degree of impedance of the oxide film pores to the electric field, in an optional embodiment, the calculation of the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and the calculation of a characteristic difference index representing the oxide film pore impedance distribution based on the numerical deviation, includes: The characteristic difference index within the preset monitoring period is calculated using the following formula. : in, Let be the instantaneous response potential at the i-th sampling point. As the reference equilibrium potential, This indicates the absolute value operation, the... The unit is volt.

[0020] Obtain the voltage of each sampling point within the preset monitoring period. Relative to the reference equilibrium potential The absolute deviation. For example, if the sampling voltage is 152.3V and the reference potential is 150.0V at a certain moment, then the absolute deviation at that point is 2.3V. By summing the deviation values ​​of N sampling points and taking the average, a characteristic difference index reflecting the overall fluctuation amplitude is obtained. If the oxide film has a uniform pore distribution and good conductivity, the voltage fluctuation is small, and the calculated... The value is low; conversely, if the pores are blocked or unevenly distributed, causing sudden changes in local resistivity, the voltage will oscillate violently, leading to... The value increased.

[0021] S3, using the characteristic difference index to calculate the voltage compensation factor through a preset compensation algorithm, multiplying the basic set voltage by the voltage compensation factor to obtain the execution voltage, and performing electrophoretic deposition on the workpiece under the execution voltage; simultaneously monitoring the amount of charge transfer during the deposition process, and combining the value of the execution voltage and the characteristic difference index, calculating the thermal conduction hysteresis coefficient of the deposited film through a thermal impedance equivalent model; The preset base voltage is 100 volts to 120 volts; the compensation algorithm is set to a mapping relationship. When the characteristic difference index shows that the impedance is too high, the calculated voltage compensation factor is greater than 1.0, for example, 1.05 or 1.1; when the characteristic difference index shows that the impedance is too low, the voltage compensation factor is less than 1.0, for example, 0.95. The base voltage is multiplied by this factor to obtain the execution voltage, for example, adjusted from 110 volts to 115.5 volts. The execution voltage is output using a rectified power supply to maintain a stable voltage for electrophoretic deposition on the workpiece. The deposition time lasts for 2 to 3 minutes to ensure uniform coating thickness.

[0022] During the electrophoretic deposition process, the current change curve over time is recorded in real time using a current transformer, and the total charge transfer is obtained by integrating the current over time. This charge transfer corresponds to the deposition amount and wet film thickness of the electrophoretic coating. The thermal impedance equivalent model uses the wet film thickness, the pore structure reflected by the characteristic difference index, and the density reflected by the execution voltage as input variables to simulate the resistance of heat transfer from the film surface to the bottom interface of the film. If the film is thick and the pores are dense, the heat conduction hysteresis coefficient calculated by the model is large, indicating that more time or higher energy is required for heat to penetrate the film. If the film is thin or porous, the hysteresis coefficient is small.

[0023] In an optional embodiment, the step of calculating a voltage compensation factor using the characteristic difference index through a preset compensation algorithm, and multiplying the base setting voltage by the voltage compensation factor to obtain the execution voltage, includes: The voltage compensation factor is calculated using the following formula. : Where K is a dimensionless adjustment coefficient. Reference normalized voltage; Obtain the basic setting voltage Through formula Calculated execution voltage ,in The unit is volt.

[0024] Specifically, an adjustment coefficient K=0.02 is used as the sensitivity control parameter to prevent excessive voltage adjustment from causing deposition instability; at the same time, a normalized reference voltage is set. V eliminates the influence of dimensions. Assume the characteristic difference index calculated above... If the voltage is 5V, the compensation term is calculated to be 0.1, thus yielding the voltage compensation factor. This indicates that the system detected a high impedance in the oxide film, requiring a 10% increase in driving force.

[0025] The control system reads the preset base voltage. For example, the standard voltage set in the process is 120V. This voltage value is then compared with the calculated compensation factor. Multiplying by 1.1 yields the actuation voltage applied to the workpiece. V. Through the aforementioned real-time feedback mechanism, an appropriate electrophoretic voltage can be output to address the differences in oxide film state between different batches or even different workpieces, overcoming the voltage division effect caused by film impedance and ensuring the deposition of the electrophoretic coating deep within the pores. Figure 3 .

[0026] In an optional embodiment, the synchronous monitoring of charge transfer during the deposition process, combined with the value of the execution voltage and the characteristic difference index, calculates the thermal conduction hysteresis coefficient of the deposited film using a thermal impedance equivalent model, including: By time interval Record the instantaneous current value i(t) during the deposition process, and calculate the total charge transfer Q during the deposition process by time integration: in This represents the total deposition time. Based on the Joule heating effect and heat conduction theory, the total electrical energy during the deposition process is positively correlated with the heat absorbed by the film layer, while the film structure affects the heat conduction efficiency. Characteristic difference index This reflects the non-uniformity of the oxide film pores, and these microstructural differences further affect the heat conduction path. Therefore, combining the two factors to construct the heat conduction hysteresis coefficient is crucial. . Calculated using the following formula: Wherein, the thermal constant The unit was determined experimentally to be joules. -1 ,make sure It is a dimensionless number.

[0027] Based on the positive correlation between the Joule heating effect and the thermal resistance of the film, the higher the deposition voltage, the greater the charge, and the more uneven the film impedance, the more easily thermal hysteresis will occur within the coating during curing. Therefore, the formula utilizes the thermal constant. And combined with the execution voltage The characteristic difference index term is used to correct and weight the charge Q. Assuming the Q value is large and... Increase the calculated heat transfer hysteresis coefficient The increased size of the coating indicates that a longer thermal penetration time is required during baking to achieve complete cross-linking, thus reflecting the specific requirements of the coating microstructure for thermodynamic processes.

[0028] In an optional embodiment, during the electrophoretic deposition process, the control system acquires the loop current i(t) in real time at 0.1-second intervals and calculates the total charge transfer amount through discrete integration. For example, when the deposition time is 180 seconds and the average current is 2.0 amperes, Q is approximately 360 coulombs. This is combined with the characteristic difference index... For example, 5.0 volts and reference voltage For example, the voltage compensation factor calculated for 1.0 volts. For example, in 1.1, the system uses a base setting voltage of 110 volts to derive the execution voltage. It is 121 volts. Then, , and Substituting into the above formula, where the thermal constant... The value was determined experimentally to be 1.0 × 10⁻⁶. -5 joule -1 Substituting the numerical values, we get ...

[0029] S4. Based on the thermal conduction hysteresis coefficient, the preset curing process parameters are modified to generate a target curing curve that includes segmented temperature change rate and constant temperature duration, and the thermal crosslinking reaction window of the film layer is matched; the workpiece that has completed electrophoretic deposition is cleaned and drained, and thermal crosslinking curing is performed according to the target curing curve to obtain a high corrosion resistant matting electrophoretic aluminum profile.

[0030] The preset curing process parameters are usually a single heating rate and a fixed holding time, such as heating at 10°C per minute to 180°C and holding for 30 minutes. The control system reconstructs the heating process into a segmented mode based on the thermal hysteresis coefficient. For example, the first segment heats at 8°C per minute to 100°C, and the second segment heats at 5°C per minute to 180°C to provide sufficient thermal conduction buffer for the thick film layer. At the same time, the holding time is extended using a correction formula, modifying 30 minutes to 35 minutes or 40 minutes to ensure complete cross-linking of the underlying resin. Conversely, if the hysteresis coefficient is small, the holding time is appropriately shortened to prevent overheating and yellowing.

[0031] After deposition, the workpiece is removed from the electrophoresis tank and washed with two RO water rinses and one pure water spray to remove surface paint. It is then left to drain or air-dried in the draining area. The workpiece is then sent to the curing oven, where the temperature control system strictly follows the reconstructed target curing curve generated above. Under the action of segmented heating and constant temperature, the electrophoretic paint film on the surface of the workpiece undergoes a uniform cross-linking reaction from the outside to the inside. The matte particles are tightly bonded to the resin matrix. After curing is completed and the workpiece is cooled and removed from the oven, a high corrosion-resistant matte electrophoretic aluminum profile with a soft and consistent surface gloss, a dense coating, and no micro-cracks can be obtained.

[0032] In an optional embodiment, the step of modifying the preset curing process parameters based on the thermal conduction hysteresis coefficient to generate a target curing curve including segmented temperature change rates and isothermal duration includes: The construction of the three-stage stepped heating curve and the determination of the heating rate are based on pre-stored process mapping rules. Specifically, a rule related to the heat conduction hysteresis coefficient is pre-set within the system. The associated parameter table, which will The system is divided into different intervals, and for each interval, three transition temperatures and heating rates for each stage are defined. For example: when When 5 < 5, the three speed segments are [10, 8, 5] ℃ / min; when 5 ≤ When <15, the rate is adjusted to [8,5,3]℃ / min; when When the temperature is ≥15, the temperature / min is [5,3,1]. The system calculates the temperature in real time. It automatically matches the range to which it belongs and calls the corresponding heating rate and inflection temperature, thereby generating a target heating curve with three different slopes from room temperature to the target curing temperature.

[0033] Calculate the duration of constant temperature using a function. : in, This is the standard isothermal duration for the curing process. As a time adjustment factor; As the temperature reaches The duration of the isothermal period is then used to generate the target curing curve by combining the heating rates of the three stages.

[0034] Specifically, the preset standard constant temperature duration Minutes, by utilizing the time adjustment factor Minutes are used to calculate the actual required isothermal duration using the square root function. For example, if the calculated result is... The correction term is 2 minutes, which determines the duration of constant temperature. It lasts 32 minutes.

[0035] The generated control commands will include the three temperature-changing processes and the corrected 32-minute isothermal process, forming a specific target curing curve for the thermal resistance characteristics of this particular workpiece, such as... Figure 4 .

[0036] In an optional embodiment, the step of cleaning and draining the workpiece after electrophoretic deposition and performing thermal crosslinking curing according to the target curing curve includes: The workpiece that has completed electrophoretic deposition is rinsed twice with pure water with a conductivity of less than 20 μS / cm. Hang the cleaned workpiece vertically for 10 minutes to allow the surface moisture to drain naturally. The drained workpiece is sent into the curing oven, and the air temperature in the curing oven is strictly controlled to follow the temperature and time settings of the target curing curve to complete the thermal crosslinking curing.

[0037] Specifically, after the workpiece is removed from the electrophoresis tank, it enters the ultrafiltration water washing system, where it undergoes two immersion cleanings using high-purity deionized water with a conductivity of less than 20 μS / cm. This washes away the adhering paint and residual bath liquid, preventing blemishes after curing, and also recovers the expensive electrophoretic paint. After cleaning, the workpiece is held vertically suspended for 10 minutes, allowing excess water to drip off naturally under gravity, preventing watermark defects during furnace loading.

[0038] After being drained, the workpieces are conveyed into a hot air circulating curing oven via a conveyor chain. At this point, the curing oven's control system no longer executes a single, fixed program, but instead calls upon the aforementioned generated program, which includes segmented heating and constant temperature durations. The target curing curve is determined. An in-furnace temperature sensor provides real-time feedback of the air temperature. By adjusting the heating power, the system strictly tracks the set three-stage heating rate and the corrected isothermal time to ensure that the paint film on each workpiece can complete a full cross-linking reaction under the thermal resistance environment where the movement of macromolecular chain segments is hindered, thus achieving optimal physical and mechanical properties.

[0039] In the second embodiment, the present invention also proposes a processing system for high corrosion-resistant electrophoretic aluminum profiles, comprising the following modules: The acquisition module is used to perform anodizing treatment on aluminum alloy substrate to obtain a workpiece with a porous oxide film; the workpiece is placed in the electrophoresis tank to construct an electrophoresis circuit, and the instantaneous response potential of the workpiece surface is acquired at high frequency during the preset monitoring period at the beginning of power-on, and the reference equilibrium potential of the tank system is obtained. A construction module is used to calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and to calculate the characteristic difference index representing the pore impedance distribution of the oxide film based on the numerical deviation. The calculation module is used to calculate the voltage compensation factor using the feature difference index through a preset compensation algorithm, multiply the base setting voltage by the voltage compensation factor to obtain the execution voltage, and perform electrophoretic deposition on the workpiece under the execution voltage; simultaneously monitor the amount of charge transfer during the deposition process, and calculate the thermal conduction hysteresis coefficient of the deposited film by combining the value of the execution voltage and the feature difference index through a thermal impedance equivalent model. The execution module is used to modify the preset curing process parameters based on the thermal conduction hysteresis coefficient, generate a target curing curve including segmented temperature change rate and constant temperature duration, and match the thermal crosslinking reaction window of the film layer; clean and drain the workpiece after electrophoretic deposition, and perform thermal crosslinking curing according to the target curing curve to obtain a high corrosion resistant matting electrophoretic aluminum profile.

[0040] In an optional embodiment, the step of acquiring the instantaneous response potential of the workpiece surface at high frequency during a preset monitoring period at the initial stage of power-on, and obtaining the reference equilibrium potential of the bath system, includes: The preset monitoring period is after power-on. Instant Second; With sampling frequency The voltage values ​​on the workpiece surface are collected at Hz within the preset monitoring period to obtain a voltage sequence set. , where N is the total number of sampling points; Before energizing, the open-circuit potential of the workpiece in the electrophoresis bath is measured using a reference electrode, and this open-circuit potential is defined as the reference equilibrium potential of the bath system. .

[0041] In an optional embodiment, calculating the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and calculating a characteristic difference index representing the oxide film pore impedance distribution based on the numerical deviation, includes: The characteristic difference index within the preset monitoring period is calculated using the following formula. : in, Let be the instantaneous response potential at the i-th sampling point. As the reference equilibrium potential, This indicates the absolute value operation, the... The unit is volt.

[0042] In an optional embodiment, the step of calculating a voltage compensation factor using the characteristic difference index through a preset compensation algorithm, and multiplying the base setting voltage by the voltage compensation factor to obtain the execution voltage, includes: The voltage compensation factor is calculated using the following formula. : Where K is a dimensionless adjustment coefficient. Reference normalized voltage; Obtain the basic setting voltage Through formula Calculated execution voltage ,in The unit is volt.

[0043] In an optional embodiment, the synchronous monitoring of charge transfer during the deposition process, combined with the value of the execution voltage and the characteristic difference index, calculates the thermal conduction hysteresis coefficient of the deposited film using a thermal impedance equivalent model, including: By time interval Record the instantaneous current value i(t) during the deposition process, and calculate the total charge transfer Q during the deposition process by time integration: in This represents the total deposition time. The total heat production is corrected using the characteristic difference index, and the heat transfer hysteresis coefficient is calculated using the following formula. : Wherein, the thermal constant The unit was determined experimentally to be joules. -1 ,make sure It is a dimensionless number.

[0044] In an optional embodiment, the step of modifying the preset curing process parameters based on the thermal conduction hysteresis coefficient to generate a target curing curve including segmented temperature change rates and isothermal duration includes: Calculate the duration of constant temperature using a function. : in, This is the standard isothermal duration for the curing process. As a time adjustment factor; As the temperature reaches the standard curing constant temperature The duration of the subsequent constant temperature.

[0045] In an optional embodiment, the anodizing treatment of the aluminum alloy substrate to obtain a workpiece with a porous oxide film includes: An aluminum alloy substrate was placed as the anode in an electrolyte with a sulfuric acid concentration of 170 g / L. The electrolyte temperature is kept constant at 20℃; The current density is Electrolysis is performed using direct current for 30 minutes; A porous anodic oxide film with a thickness of 12 micrometers is formed on the surface of an aluminum alloy substrate, which is then washed with water and used as the workpiece to be processed.

[0046] In an optional embodiment, the step of cleaning and draining the workpiece after electrophoretic deposition and performing thermal crosslinking curing according to the target curing curve includes: The workpiece that has completed electrophoretic deposition is rinsed twice with pure water with a conductivity of less than 20 μS / cm. Hang the cleaned workpiece vertically for 10 minutes to allow the surface moisture to drain naturally. The drained workpiece is sent into the curing oven, and the air temperature in the curing oven is strictly controlled to follow the temperature and time settings of the target curing curve to complete the thermal crosslinking curing.

[0047] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0048] The functional modules shown in the above-described block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0049] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0050] The aspects of this application have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0051] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A processing method for high corrosion-resistant electrophoretic aluminum profiles, characterized in that, include: Anodizing is performed on an aluminum alloy substrate to obtain a workpiece with a porous oxide film. The workpiece to be processed is placed in the electrophoresis tank to construct an electrophoresis circuit. During the preset monitoring period at the beginning of power-on, the instantaneous response potential of the workpiece surface is collected at high frequency, and the reference equilibrium potential of the tank system is obtained. Calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and calculate the characteristic difference index representing the pore impedance distribution of the oxide film based on the numerical deviation; The voltage compensation factor is calculated using the characteristic difference index through a preset compensation algorithm. The basic set voltage is multiplied by the voltage compensation factor to obtain the execution voltage. Electrophoretic deposition is then performed on the workpiece under the execution voltage. The amount of charge transfer during the deposition process is monitored synchronously. Combined with the value of the execution voltage and the characteristic difference index, the thermal conduction hysteresis coefficient of the deposited film is calculated through the thermal impedance equivalent model. Based on the thermal conduction hysteresis coefficient, the preset curing process parameters are modified to generate a target curing curve that includes segmented temperature change rate and isothermal duration, matching the thermal crosslinking reaction window of the film layer. The workpiece after electrophoretic deposition is cleaned and drained, and then thermal crosslinking curing is performed according to the target curing curve to obtain a high corrosion-resistant, matte electrophoretic aluminum profile.

2. The method according to claim 1, characterized in that, The step of acquiring the instantaneous response potential of the workpiece surface at high frequency during a preset monitoring period at the initial stage of power-on, and obtaining the reference equilibrium potential of the bath system, includes: The preset monitoring period is after power-on. Instant Second; With sampling frequency The voltage values ​​on the workpiece surface are collected at Hz within the preset monitoring period to obtain a voltage sequence set. , where N is the total number of sampling points; Before energizing, the open-circuit potential of the workpiece in the electrophoresis bath was measured using a reference electrode, and this open-circuit potential was defined as the reference equilibrium potential of the bath system. .

3. The method according to claim 1, characterized in that, The calculation of the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and the calculation of a characteristic difference index representing the oxide film pore impedance distribution based on the numerical deviation, includes: The characteristic difference index within the preset monitoring period is calculated using the following formula. : in, Let be the instantaneous response potential at the i-th sampling point. As the reference equilibrium potential, This indicates the absolute value operation, the... The unit is volt.

4. The method according to claim 1, characterized in that, The step of calculating a voltage compensation factor using the characteristic difference index through a preset compensation algorithm, and multiplying the base setting voltage by the voltage compensation factor to obtain the execution voltage, includes: The voltage compensation factor is calculated using the following formula. : Where K is a dimensionless adjustment coefficient. Reference normalized voltage; Obtain the basic setting voltage Through formula Calculated execution voltage ,in The unit is volt.

5. The method according to claim 4, characterized in that, The synchronous monitoring of charge transfer during the deposition process, combined with the value of the execution voltage and the characteristic difference index, calculates the thermal conduction hysteresis coefficient of the deposited film using a thermal impedance equivalent model, including: By time interval Record the instantaneous current value i(t) during the deposition process, and calculate the total charge transfer Q during the deposition process by time integration; The total heat production is corrected using the characteristic difference index, and the heat transfer hysteresis coefficient is calculated using the following formula. : Wherein, the thermal constant The unit was determined experimentally to be joules. -1 ,make sure It is a dimensionless number.

6. The method according to claim 1, characterized in that, The step of correcting the preset curing process parameters based on the thermal conduction hysteresis coefficient to generate a target curing curve including segmented temperature change rate and isothermal duration includes: Calculate the duration of constant temperature using a function. : in, This is the standard isothermal duration for the curing process. As a time adjustment factor; As the temperature reaches the standard curing constant temperature The duration of the subsequent constant temperature.

7. The method according to claim 1, characterized in that, The process of anodizing an aluminum alloy substrate to obtain a workpiece with a porous oxide film includes: An aluminum alloy substrate was placed as the anode in an electrolyte with a sulfuric acid concentration of 170 g / L. The electrolyte temperature is kept constant at 20℃; The current density is Electrolysis is performed using direct current for 30 minutes; A porous anodic oxide film with a thickness of 12 micrometers is formed on the surface of an aluminum alloy substrate, which is then washed with water and used as the workpiece to be processed.

8. The method according to claim 1, characterized in that, The process of cleaning and draining the workpiece after electrophoretic deposition, and then performing thermal crosslinking curing according to the target curing curve, includes: The workpiece that has completed electrophoretic deposition is rinsed twice with pure water with a conductivity of less than 20 μS / cm. After cleaning, hang the workpiece vertically for 10 minutes to allow the surface moisture to drain naturally. The drained workpiece is sent into the curing oven, and the air temperature in the curing oven is strictly controlled to follow the temperature and time settings of the target curing curve to complete the thermal crosslinking curing.

9. A processing system for high corrosion-resistant, photosensitive aluminum profiles, characterized in that, Includes the following modules: The acquisition module is used to perform anodizing treatment on aluminum alloy substrates to obtain workpieces with porous oxide films. The workpiece to be processed is placed in the electrophoresis tank to construct an electrophoresis circuit. During the preset monitoring period at the beginning of power-on, the instantaneous response potential of the workpiece surface is collected at high frequency, and the reference equilibrium potential of the tank system is obtained. A construction module is used to calculate the numerical deviation between the instantaneous response potential and the reference equilibrium potential, and to calculate the characteristic difference index representing the pore impedance distribution of the oxide film based on the numerical deviation. The calculation module is used to calculate the voltage compensation factor using the feature difference index through a preset compensation algorithm, multiply the base setting voltage by the voltage compensation factor to obtain the execution voltage, and perform electrophoretic deposition on the workpiece under the execution voltage. The amount of charge transfer during the deposition process is monitored synchronously. Combined with the value of the execution voltage and the characteristic difference index, the thermal conduction hysteresis coefficient of the deposited film is calculated through the thermal impedance equivalent model. The execution module is used to modify the preset curing process parameters based on the thermal conduction hysteresis coefficient, generate a target curing curve including segmented temperature change rate and isothermal duration, and match the thermal crosslinking reaction window of the film layer. The workpiece after electrophoretic deposition is cleaned and drained, and then thermal crosslinking curing is performed according to the target curing curve to obtain a high corrosion-resistant, matte electrophoretic aluminum profile.

10. The system according to claim 9, characterized in that, The step of acquiring the instantaneous response potential of the workpiece surface at high frequency during a preset monitoring period at the initial stage of power-on, and obtaining the reference equilibrium potential of the bath system, includes: The preset monitoring period is after power-on. Instant Second; With sampling frequency The voltage values ​​on the workpiece surface are collected at Hz within the preset monitoring period to obtain a voltage sequence set. , where N is the total number of sampling points; Before energizing, the open-circuit potential of the workpiece in the electrophoresis bath was measured using a reference electrode, and this open-circuit potential was defined as the reference equilibrium potential of the bath system. .

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