Influence of N+ implantation on structure, morphology, and corrosion behavior of Al in NaCl solution**This work was funded by the University of Tehran.

Abstract

Structural and morphological changes as well as corrosion behavior of N+ implanted Al in 0.6 M NaCl solution as function of N+ fluence are investigated. The x-ray diffraction results confirmed AlN formation. The atomic force microscope (AFM) images showed larger grains on the surface of Al with increasing N+ fluence. This can be due to the increased number of impacts of N+ with Al atoms and energy conversion to heat, which increases the diffusion rate of the incident ions in the target. Hence, the number of the grain boundaries is reduced, resulting in corrosion resistance enhancement. Electrochemical impedance spectroscopy (EIS) and polarization results showed the increase of corrosion resistance of Al with increasing N+ fluence. EIS data was used to simulate equivalent electric circuits (EC) for the samples. Strong dependence of the surface morphology on the EC elements was observed. The scanning electron microscope (SEM) analysis of the samples after corrosion test also showed that the surfaces of the implanted Al samples remain more intact relative to the untreated Al sample, consistent with the EIS and polarization results.