Abstract
In the present work, the effects of 5-(3-aminophenyl)-tetrazole (APTA) on the corrosion inhibition of magnesium in Arabian Gulf seawater (AGS) and 3.5 wt.% NaCl solutions were reported. Different experimental techniques namely, weight-loss (WtL), potentiodynamic polarization (PDP), potentiostatic current-time (CCT), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) with X-ray analyzer (EDX) were employed. It has been found that AGS has almost similar effect compared to 3.5 wt.% NaCl on Mg uniform corrosion but it has higher effect on the Mg pitting and microbial induced corrosion than NaCl has. The presence of 1x10(-3) M APTA and the increase of its concentration to 5x10(-3) M highly reduce the corrosion of Mg in both AGS and NaCl solutions. This was confirmed by the decrease of corrosion current and corrosion rate as well as the increase of surface and polarization resistances for Mg after its immersion in AGS and NaCl containing APTA molecules. The surface morphology obtained by SEM and profile analysis acquired by EDX stated that the surface of Mg is compacted and protected in the presence of APTA molecules.