Stearic Acid Coated MgO Nanoplate Arrays as Effective Hydrophobic Films for Improving Corrosion Resistance of Mg-Based Metallic Glasses

Mg-based metallic glasses (MGs) are widely studied due to their high elasticity and high strength originating from their amorphous nature. However, their further application in many potential fields is limited by poor corrosion resistance. In order to improve this property, an MgO nanoplate array layer is first constructed on the surface of Mg-based MGs by cyclic voltammetry (CV) treatments. In this situation, the corrosion resistance and hydrophilicity of the material are enhanced. Then, stearic acid (SA) can effectively adhere onto the surface of the MgO layer to form a superficial hydrophobic film with a water contact angle (WCA) of 131°. As a result, the SA coated MgO hydrophobic film improves the corrosion resistance of Mg-based MGs in 3.5 wt.% NaCl solution obviously. In addition, the effects of four technological parameters (solution concentration, sweep rate, cycle number, and reaction temperature) in the CV process on the morphology and size of nano-products are investigated in detail. The work proposes a new method for the creation of nanostructures on the surface of materials and provides a new idea to increase the corrosion resistance of MGs. The related method is expected to be applied in wider fields in future.