The study of the electrochemical graining process in NaBO 2-H3BO3 solution and grain appearance on the surface of aluminum alloy

The mainly process of electrochemical graining on 6063 aluminum alloy included graining at alternating current.. anodizing and chemical coloring. The graining used NaBO2- H3BO3 system as film-forming solution, proper AC current density, treating time, temperature, adding agents and solution concentration were ascertained through operating orthogonal experiment, the grain of appropriate density and width could be obtained, the grained surface of aluminum alloy presented intergranular corrosion in the graining zone, the appearance was improved after anodizing, enough thick anodizing film could make intergranular corrosion eliminated. Cyclic voltammetry experiment was used to preliminarily explaine the grain process, the main cause of graining zone formation was hydrogen evolution.