Study On Acrylic Electrophoresis Coating Process Of High Aluminum Silicon Alloy

Due to the addition of Si, Mg up to13%-15%into the alloy, High Aluminum silicon alloy has high intensity and good casting performance, but also high environmental sensitivity. The sensitivity can hardly meet the demands of weather resistance and decorative property of building materials. Therefore, the study on Electrophoresis Coating Process of High Aluminum Silicon Alloy has vital significance to promote its use in industrial application.This paper selects the alloy as the research object, and adopts orthogonal experiment to obtain the best scheme as follows:content of sulfuric acid170g/L, oxide time30minutes, oxide temperature20℃and current density1.7A/dm. And then, the alloy receives electrophoretic coating treatment, which solution containing acrylic resin used as main film forming substance, added pigments and additives. Through the analysis of impact factors and results of orthogonal test, the optimal preparation conditions of Electrophoresis Coating are as follows:electrophoretic voltage150V, time210s, temperature25℃, pole distance10cm and solid content12%.The microcosmic morphology of anodic oxide film and red electrophoretic painting films are characterized by SEM. The results show that the dye has been depositted in porosity films, the surface of painting film is compact and homogeneous and the thickness of compound film is20-45μm. The physical performance tests of the films show that its adhesive force reaches0grade, rigidity up to3H, and good washing resistance. Its chemical corrosion resistance tests show that electrophoretic coating films have high capability of acid and salt resistance after immersion of24h. The capability of alkali resistance becomes stronger with voltage increasing. Moreover, the film has good salt fog resistance, and its appearance quality>9grade, boiling water resistance0grade and weather resistance0grade.Final results show that we can attain combined electrophoretic anodic film with good appearance and performance in the best condition of anodizing process and electrophoresis coating process by adding different pigment.