Inhibiting action of fruits of Terminalia chebula on 6063 aluminum alloy in sodium hydroxide solution

The inhibition characteristics of aqueous extract of fruits of terminalia chebula (tce) has been studied as a possible source of natural inhibitor for corrosion of 6063 aluminum alloy in sodium hydroxide solution by weight loss method and potentiodynamic polarization method. the effect of inhibitor was studied at different concentrations of medium (0.5 m,1.0 m,2.0 m),by varying inhibitor concentration and temperature in the range of 30 °c to 50 °c. kinetic and thermodynamic parameters were evaluated and discussed in detail. inhibition efficiency increased with concentration of inhibitor and decreased with temperature as well as with the concentration of medium. the adsorption of tce on metal surface obeyed the langmuir adsorption isotherm. tce acted as mixed inhibitor and followed physical adsorption on the surface of metal. the surface morphology of 6063 aluminum alloy,in absence and presence of tce in 0.5 m sodium hydroxide were studied using scanning electron microscopy (sem) and energy-dispersive x-ray spectroscopy (edx).