Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment

Abstract The microstructure and corrosion processes of a friction stir welded (FSW) 7075-T6 aluminum alloy joint, before after anodizing surface treatment, have been characterized by advanced techniques, the feasibility treatment as mitigation method has evaluated. results showed that different zones FSW joint had distinctly consequently behavior in NaCl solution. Stable localized occurred transitional regions between thermo-mechanically affected zone (TMAZ) heat (HAZ), was intergranular corrosion. ascribed to galvanic coupling effect Cu-rich grain boundary precipitates free (PFZs). Although subsequent sealing treatments could greatly improve resistance base metal, TMAZ/HAZ transition still much higher susceptibility than other regions. high is not difference anodic oxide film regions, but heterogeneous beneath film. present paper shown stable intrinsically stemmed from welding process itself traditional such cannot solve problem; more effective methods are awaited.