Investigation of novel heterocyclic compounds as inhibitors of Al-3Mg alloy corrosion in hydrochloric acid solutions

The inhibition of Al-3Mg alloy corrosion in 0.5 M and 1 M HCl by newly prepared compounds namely: 4-(methoxymethyl)-1, 6-dimethyl-2-oxo-1, 2- dihydropyridine-3-carbonitrile (compound A) and 4-amino-3, 5-bis[6-(methoxymethyl)-3, 4-dimethyl-2-oxo-1, 2-dihydropyridine-1-yl]-1, 2, 4-triazole-2(H) (compound B) has been studied by weight loss and potentiodynamic polarization measurements. Tafel curves showed that both compounds investigated are excellent mixed type inhibitor for Al-3Mg alloy in acidic solutions. The adsorption of these compounds obeyed the Langmuir adsorption isotherm. FTIR analysis was used to obtain information on bonding mechanism between the metallic surface and the inhibitors. The triazole derivative (compound B) is better inhibitor than pyridine derivative (compound A)