Morphological evolution and burning behavior of oxide coating fabricated on aluminum immersed in etidronic acid at high current density

Micro arcs on metal surface immersed in alkaline electrolyte have been studied by many works, but that in acidic electrolyte are rarely reported. In this work, anodizing of aluminum was carried out in etidronic acid (HEDP) at high current density to investigate the formation behavior of coating. SEM images indicate that the burning of initial film is actually caused by local oxide cracking due to the increase of compressive stress. The soft...