Corrosion Inhibition of Aluminum in Hydrochloric Acid Solutions Using Some Chalcone Derivatives

The inhibition effect of some Chalcone derivatives [3 -(4-hydroxyphenyl)-1-phenylprop-2-en-1-one as an inhibitor (1) and 3 -(4-hydroxyphenyl)-1-(4-nitrophenyl)prop-2-en-1-one as an inhibitor (2)] on the corrosion of aluminum in 0.5 M HCl solution was studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) and weight loss measurements. The results drawn from the different techniques are comparable and exhibit small discrepancy. Results for weight loss indicated that inhibitor efficiency (% IE) increased with increasing inhibitor concentration, reaching a maximum inhibiting power of 85.9, 95.7 % at 21 x 10 -6 M for inhibitors 1 and 2, respectively and decreased with increasing the temperature. Polarization studies clearly revealed that the presence of inhibitors changes the mechanism of hydrogen evolution and the metal dissolution i.e. they act as mixed type inhibitors. Some activation and adsorption thermodynamic parameters were calculated and discussed. The surface coverage of the inhibitors obeyed Langmuir adsorption isotherm.