Ionic liquid as sustainable inhibitor for corrosion of 6061 Al-10 vol% SiC_(p): Experimental and theoretical perspective

The anti-corrosive performance of an ionic liquid 1-butyl-3-methyl-1H-imidazol-3-ium hexafluorophosphate (BMIF) on corrosion of 6061Al-10 vol% SiC composite (6061 Al-CM) in 0.05 M HCl medium was investigated. Studies were carried out at temperatures ranging from 303 K to 323 K by varying inhibitor concentration. Maximum efficiency of 81 % was observed for the addition of 50 ppm BMIF at 323 K. BMIF acted as a mixed inhibitor, undergoing chemisorption by following Freundlich's adsorption isotherm. The surface morphology was studied using a scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and an atomic force microscope (AFM), which confirmed the adsorption of BMIF onto the metal surface. Mechanistic aspects of the adsorption of the inhibitor on the composite were studied in detail by quantum mechanical calculations using density functional theory (DFT). Quantum chemical descriptors obtained by DFT studies supported the adsorption capacity of the inhibitor.