Studies on the inhibition of aluminum dissolution by hexamine-halide blends

Corrosion inhibition of aluminum in hydrochloric acid solution by hexamine-halide blends (HA-KI and HA-CaCl2) was investigated using gravimetric method, open circuit potential and polarization measurements. Results showed that single additives HA and KI are moderate inhibitors, while CaCl2 is poor inhibitor for corrosion inhibition of Al in 2 M HCl solution. In the presence of blends HA-KI and HA-CaCl2, the corrosion resistance of aluminum is improved and the corrosion rate (CR) and corrosion current (Ic) are reduced significantly, so the inhibition efficiency (IE) and polarization resistance (Rp) are increased. With the mixed inhibitors, there is a compact adsorbed film formation on the surface of Al, due to a synergistic action between the halides ions and HA.