Effect of Crystallographic Orientation on the Inhibition Behavior of 1,5-Naphthalenediol on Pure Aluminum

Crystallographic orientation is an important factor to affect the inhibition performance of metal materials, while the influence of crystallographic orientation of the pure aluminum metal on the electrochemical noise features during inhibition process is still unclear. In the present work, the inhibition behavior of 1,5-naphthalenediol on pure aluminum with different crystallographic orientations has been investigated using electrochemical techniques as well as some surface characterizations. Electrochemical impedance spectroscopy (EIS) results indicated that the pure aluminum specimen with (111) crystallographic orientation presented the highest corrosion resistance. The value of noise resistance calculated from electrochemical potential and current noise was positively correlated to the charge transfer resistance (Rct) from EIS results. The parameter of corrosion energy (Ec) proposed from wavelet analysis of electrochemical noise data revealed an oppositely variation trend to Rct with different crystallographic orientations. This observation was further confirmed by the X-ray photoelectron spectroscopy measurements. Lower Ec corresponded to stronger adsorption of inhibitors and Ec can be utilized as a potential criterion to estimate the corrosion rate and eventually ascertain the effect of crystallographic orientation on the inhibition performance.