The Formation of Superhydrophobic Surface on the AZ31 Mg Alloy Using Chemical Immersion Method and The Investigation of Its Corrosion Behavior

Considering the large functions of Mg alloys in the various industries, their weak surface properties including resistance to oxidation and corrosion have been regarded as the primary challenge to commercializing them. Obtaining superhydrophobic surfaces have been an efficient way for enhancement of the corrosion resistance feature which has drawn much attention. In the present study, the formation of superhydrophobic structure (SHPs) on the Mg alloy was investigated by immersion into the CuCl2 and NiSO4 solutions following by soaking in the stearic acid (SA) solution. The contact angle of the obtained surface after the process measured about 151.5 °. Fourier transform infrared spectroscopy (FTIR) spectra showed the presence of some bonds of SA on the surface of Mg alloy. Besides, FESEM morphology of SHP Mg alloy illustrated a flakelike morphology which could prevent corrosive electrolyte penetration toward Mg surface. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests illustrated that the corrosion resistance of SHP Mg was greater than Mg alloys about 1000 times which could be due to the presence of rough morphology and adsorbed hydrophobic molecules.