Exploration the inhibition mechanism of sodium dodecyl sulfate on Mg alloy

The inhibition mechanism of sodium dodecyl sulfate (SDS) on Mg alloy in 3.5 wt. % NaCl solution was thoroughly investigated by means of SEM, EPMA, XPS, TEM and electrochemical corrosion tests. The active Mg surface is covered by a hydrophobic outer corrosion layer and a passive inner oxide layer in the presence of SDS, which suppress the cathodic hydrogen evolution and anodic dissolution of the substrate. The electrochemical reaction kinetics is inhibited due to adsorption of SDS in the corrosion products, while the oxidation reaction of the substrate is facilitated by the hydrophobic outer corrosion layer.