Corrosion inhibition of Aluminum in 1 M phosphoric acid solutions using some Chalcones derivatives and synergistic action with halide ions

Abstract

The purpose of this paper is to investigate the inhibition effect of some Chalcone derivatives on the corrosion behavior of aluminum in 1 M phosphoric acid solutions with and without Chalcone derivatives and to investigate the influence of halide additives namely: KCl, KBr and KI on the inhibition efficiency of aluminum. For this purpose, polarization (DC) and weight loss measurements were used. To increase the inhibition efficiency, halide anions were added to the corrosive medium. The effect of temperature also was studied over the range 30 to 50°C. Thermodynamic parameters (ΔH*, ΔS*) were calculated and discussed. The results indicated that the corrosion of aluminum was affected by the addition of Chalcone derivatives in 1 M H3PO4. The efficiency of Chalcone derivatives increases with the increase in the derivatives concentration but decreases with a rise in temperature. The effect of addition of halide ions to the corrosive solution increases the inhibition efficiency by more than 30%. These compounds were adsorbed on aluminum surface obeying Freundlich adsorption isotherm and they behave as mixed type inhibitors. The main objectives of this study were to gain some insight into the protection of aluminum in 1 M H3PO4 medium using some Chalcone derivatives. Key words: Corrosion inhibition, aluminum, synergistic effect, H3PO4, Chalcone derivatives.