5-(3-Pryridyl)-4H-1,2,4-triazole-3-thiol as Potential Corrosion Inhibitor for AA6061 Aluminium Alloy in 0.1 M Hydrochloric Acid Solution

Resumo

Corrosion inhibition performance of 5-(3-Pryridyl)-4H-1,2,4-triazole-3-thiol on aluminium alloy AA6061 in 0.1 M HCl solution was tested by the weight loss method, potentiodynamic polarization and electrochemical impedance spectroscopy. The effect of an increase in temperature and a change in the concentration of the inhibitor were studied. The results indicated that with an increase in the concentration of the inhibitor and temperature the inhibition efficiency also increased. The inhibition efficiency as high as 94.1% was found at 60°C for 40 ppm of the inhibitor. By the perusal of thermodynamic and activation parameters, it is found that adsorption of the studied inhibitor takes place through chemisorption. The inhibitor agrees the Langmuir adsorption isotherm and acts as a mixed type inhibitor. Thermodynamic parameters also unveiled that the process of adsorption on the metal surface takes place through chemisorption. The formation of a protective film on the metal surface was confirmed by scanning electron microscopy. From the mechanism of corrosion inhibition, it is possible to deduce the formation of a coordination bond between the inhibitor and the metal surface. The inhibition nature of the molecule was explained by theoretical studies.