Inhibition of Aluminum Alloy 7025 in Acid Solution Using Sulphamethoxazole

Corrosion behavior of aluminum alloy 7025 was investigated in hydrochloric acid (pH=1) containing 0.6 mol.dm -3 NaCl in the existence and absence of diverse concentrations of sulphamethoxazole as environmentally friendly corrosion inhibitor over the temperature range (298-313)K.Electrochemical polarization method using potentiostatic technique was employed.The inhibition efficiency has been raised with increased sulphamethoxazole concentration but lessened at temperature increases.The highest efficiency value was 96.5 at 298 K and 2 x10 -4 mol.dm -3 concentration of sulphamethoxazole.The sulphamethoxazole adsorption was agreed with Langmuir adsorption isotherm.Some thermodynamic parameter (△Gads) and activation energy (Ea) were determined to demonstrate the process of corrosion inhibiting.The kinetic parameters were calculated using Arrhenius equation.An appropriate mechanism has been suggested for aluminum corrosion in acidic medium.The results show that sulphamethoxazole is a mixed type inhibitor.The surface morphology of uninhibited and inhibited samples was investigated using an optical microscope.