Gravimetric, Electrochemical and Theoretical Study on Corrosion of AA6061/3wt% SiC/3wt% B4C Hybrid Composite in Acid Medium Using EDTA

The corrosion behaviour of Al6061/3wt%SiC/3wt%B4C hybrid composite was investigated in the presence of 0.5M HCl medium using gravimetric, electrochemical, and theoretical methods. In the present work, ethylenediaminetetraacetic acid disodium (EDTA) was used as an eco-friendly inhibitor. EDTA showed mixed inhibitor behavior, and its inhibition performance decreased with rising temperature from 303 to 323 K. EDTA evinced maximum inhibition efficiency of 82 % at 1.074 mM. The kinetic and thermodynamic results controlling corrosion were evaluated. The inhibition process occurred through the adsorption of EDTA on the hybrid composite sample, which obeyed Langmuir's adsorption isotherm. The experimental results were validated by theoretical study. The corroded and inhibited specimen's surface analysis performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed the adsorption of EDTA on the hybrid composite surface.