Imidazole-based ionic liquid as a corrosion inhibitor for aluminum alloy and it’s composite in HCl – A comparative study

Abstract

The corrosion inhibition characteristics of ionic liquid 1-butyl-3-methyl-1H-imidazol-3-ium hexafluorophosphate (BMIF) on the corrosion behavior of 6061 Al–10 vol(%) SiC(p) composite (6061 Al-CM) and 6061 aluminum alloy(base alloy) were studied at different temperatures in 0.1 M HCl medium. The potentiodynamic polarisation technique and AC impedance spectroscopy (EIS) were used for corrosion rate determination. The obtained results showed that inhibition efficiencies increased with the increase in inhibitor concentration and temperature. The adsorption of BMIF on both 6061 Al–CM and base alloy was through chemisorption obeying the Freundlich adsorption isotherm. From the adsorption data thermodynamic parameters were evaluated. Surface morphology studies confirmed the adsorption of BMIF. Maximum inhibition efficiencies were 78 % for 6061 Al-CM and 68 % for base alloy for the concentration of 50 ppm BMIF in 0.1 M HCl at 323 K.