Effect Of Auxiliary Anode On Electrophoretic Paint Film Thickness And Optimal Design

Electrophoretic coating is the most commonly used process in metal anticorrosion technology,and it is the basis of car anti-corrosion.Since the van-type light truck compartment is a typical fully enclosed structure,compared with the outer surface,the surface of the inner cavity of the compartment has an electric field shielding effect in the electrophoretic coating process,the paint film has weak paintability and a large difference in thickness distribution,which directly affects Anti-corrosion performance of the carriage.In this paper,a van-type light truck model of a certain company is selected,and the influence of the auxiliary anode on the paint film thickness of the interior cavity of the car is studied through electrophoresis simulation,and the auxiliary anode is optimized to improve the electric field inside the car,and the following research is carried out:(1)In view of the problem of insufficient paint film thickness on the surface of the interior cavity of the car,this study finds the research status of anti-corrosion technology at home and abroad,and analyzes the application status of numerical analysis technology in automotive electrophoretic deposition.On this basis,study the electrochemical reaction mechanism of electrophoretic coating in automobile anticorrosion process and the relevant knowledge of electrophoretic electrochemical simulation theory.(2)Obtain coating parameters and electrophoretic coating process parameters in the process of electrophoretic coating,and construct an electrophoretic simulation numerical model.Through the STAR CCM+ simulation software,the convergence of the three-dimensional model mesh is verified,and the electrophoretic coating process is simulated in the electrophoresis tank under the action of voltage,and the numerical simulation film thickness results are compared with the measured film thickness results of the actual vehicle to verify the electrophoresis simulation of the carriage the reliability of the model;(3)By studying the influence of the structure,discharge area and process voltage of the auxiliary anode on the paint film thickness of the car,it is found that the crosssectional area of the auxiliary anode has a greater influence on the paint film thickness,while the length of the auxiliary anode has less influence on the paint film thickness;By studying the influence of the discharge area on the paint film thickness,it is found that the discharge area has a great influence on the paint film thickness;the numerical law of the auxiliary anode process voltage on the paint film thickness is studied,and the optimal working voltage of the electrophoretic coating for the car is further deduced;(4)The quantitative research results were applied to the optimization of the auxiliary anode structure of a company’s electrophoresis production line.According to the process requirements,a retractable auxiliary anode was designed and applied to the electrophoretic coating production line,which improved the problem of non-painting on the surface of the inner cavity of the car.