Electrochimica Acta, Vol.44, No.14, 2445-2454, 1999
The formation and dissolution of anodic oxide films on pure aluminium in alkaline solution
The mechanisms of formation and dissolution of anodic oxide films on pure aluminium rotating disc specimens in alkaline solution have been investigated using galvanostatic anodizing, potentiostatic anodizing, potential drop experiments and impedance spectroscopy. It was found that in alkaline solution the strength of the applied electric field accelerates the formation of the anodic oxide film, while it retards its dissolution, indicating electrochemical formation of the film and a complete lack of its field-assisted dissolution. The rate of growth and the thickness of the anodic oxide film were observed to decrease with an increasing rate of specimen rotation as a result of accelerated chemical film dissolution due to rapid removal of aluminate ions from and fast supply of hydroxide ions towards the film/solution interface.
Keywords:APPLIED CURRENT-DENSITY;ELECTROCHEMICAL-BEHAVIOR;STRESSGENERATION;GROWTH-KINETICS;H2SO4 SOLUTION;ELECTROLYTES;OXIDATION;CORROSION;TUNGSTEN;ALLOYS