Corrosion Inhibition of Two Aluminum Silicon Alloys in 0.5 M HCl Solution by Some Azole Derivatives Using Electrochemical Techniques

Abstract

The inhibiting action of three derivatives of azole compounds has been investigated for the corrosion of two aluminum-silicon alloys in 0.5 M HCl solution using some electrochemical measurements such as potentiodynamic polarization, electrochemical impedance, and electrochemical frequency modulation. The morphology of the surface was examined by the scanning electron microscopy. It was found that the inhibition efficiency increases with the increase in the concentration of azole compounds. Those compounds acted as mixed inhibitors and their inhibiting effect was revealed through the formation of an adsorbed film, which blocked the active site present on the alloys. The adsorption process follows the Freundlich isotherm. The addition of Si to Al electrode increases in the corrosion protection of the alloys in the following sequence: Alloy II > Alloy I. The inhibition efficiencies obtained via different techniques are consistent with each other.