Corrosion of aluminum in aqueous solutions containing aspartic, glutamic acid with without sodium chloride

Abstract EN

The corrosion behavior of Aluminum alloy 6063 (Al 6063) in aerated aqueous solutions containing food additives namely aspartic (Asp) and glutamic (Glu) acids with / without chloride ions was studied.

Several techniques were used chemical methods (weight loss, atomic absorption) and potentiodynamic polarization measurements.

Surface morphology and surface analysis were investigated by SEM and EDX techniques.

Good consistency between the data obtained from weight loss and atomic absorption was observed.

In polarization measurements, the effect of pH, temperature, and immersion time was studied.

Polarization measurements showed that the combination of chloride ions and amino acids has a synergistic effect on Al dissolution in the acidic medium while no pronounced effect was noticed in both neutral and alkaline media.

Increasing temperature leads to an increase in corrosion current density with different extents depending on the existence of chloride ions.

Increasing immersion time increases corrosion current density for Al 6063 in amino acid solutions and the adverse effect was observed in sodium chloride solutions with / without amino acids, showing the complexity of the adsorption mechanism of both chloride and amino acids.