Effect of Crystallographic Orientation on the Initial Corrosion Behavior of Pure Aluminum in NaCl Solution

Crystallographic orientation plays a vital role in the corrosion performance of metal materials. In the present work, the effect of crystallographic orientation on the initial corrosion behavior of pure aluminum in 3.5 wt % NaCl solution was systematically investigated through both experimental and theoretical aspects. Electrochemical impedance spectroscopy (EIS) revealed that the pure aluminum single crystal with (100) orientation exhibited the largest corrosion resistance than that of the (110) and (111) orientations. The noise resistance and proposed stable pitting energy obtained from analyzing electrochemical potential and current noise were in good accordance with the EIS result. The theoretical calculations further confirmed the superior anti-corrosion performance of (100) crystallographic orientation comparing to the other two orientations. The influence of crystallographic orientations on the corrosion behavior of pure aluminum could be efficiently monitored and distinguished by the analysis of the electrochemical potential and current noise, also by the noise resistance and the proposed stable pitting energy variations.